CONS. 

T 

49 

P63 

1856 


r  ♦ 


V 


THE 


ARTIST’S  GUIDE 

AND 

MECHANIC’S  OWN  BOOK, 

EMBRACING 

THE  PORTION  OF  CHEMISTRY  APPLICABLE 

TO  THE 

V  * 

MECHANIC  ARTS, 

WITH 

ABSTRACTS  OF  ELECTRICITY,  GALVANISM,  MAG 
NETISM,  PNEUMATICS,  OPTICS,  ASTRONOMY, 

AND 

MECHANICAL  PHILOSOPHY. 

ALSO 

MECHANICAL  EXERCISES 

IN 

IRON.  STEEL,  LEAD,  ZINC,  COPPER,  AND  TIN  SOLDERING 

AND 

A  VARIETY  OF  USEFUL  RECEIPTS, 

EXTENDING 

TO  EVERY  PROFESSION  AND  OCCUPATION  OF  LIFE ; 

PARTICULARLY 

DYEING,  SILK,  WOOLLEN,  COTTON,  AND  LEATHER 
BY  JAMES  PILKINGTON. 
BOSTON: 

SANBORN,  CARTER  AND  BAZIN. 
PORTLAND : 

SANBORN  &  CARTER. 

1856. 


C  or>S 


T 


I  ^5o 


Euturod,  according  to  the  Act  ot  Congress;  in  tne  year  IS41, 

BY  ALEXANDER  V.  BLAKE, 

lu  tbs  clerk’s  office  o(  the  district  couitol  the Eoutliorn district  of 
New  York. 


THE  GETTY  CENTER 
LIBRARY 


PREPACE. 


Mechanics  generally,  having  risen  from  families 
in  the  more  humble  stations  of  society,  are  not  much 
favored  with  school  education.  Yet,  in  their  case 
may  be  seen  what  is  common  in  the  allotments  of 
Providence,  that  an  evil  is  attended  with  a  correspond¬ 
ing  benefit.  Thus,  if  poverty  obliges  many  a  youth 
to  resort  to  the  workshop  for  means  of  subsistence, 
instead  of  spending  his  time  under  tutors  in  obtain¬ 
ing  from  books  the  elementary  instruction  usually  es¬ 
teemed  necessary  to  usefulness  in  life,  it  is  a  fact  well 
known,  that  most  mechanical  pursuits  are  found 
favorable  to  mental  developement.  The  fixtures  of 
a  mill,  in  multitudes  of  cases,  seem  to  have  answered 
about  the  same  purpose  in  this  respect,  as  the  labora¬ 
tory  of  the  chemist,  or  the  philosophical  apparatus  of 
the  college  professor.  Instances  have  been  frequent 
that  the  unlettered  boy  has  risen,  step  by  step,  guided 
by  his  own  energies,  till  he  became  distinguished  for 
science  and  for  inventions  to  bless  the  whole  range 
of  society.  And  it  is  believed,  that  no  class  in  the 
community  is  more  characterized  than  mechanics  for 
the  best  of  all  possible  endowments,  the  capability 
and  habit  of  thinking  for  themselves. 


VI 


PREFACE. 


The  admission  of  this  truth  renders  it  desirable, 
that  all  possible  facilities  be  placed  within  the  reach 
of  this  most  respectable  and  valuable  portion  of  our 
community.-  Indeed,  it  is  nearly  as  certain  as  mathe¬ 
matical  demonstration,  that  if  facilities  are  placed 
within  their  reach,  the  result  will  be  auspicious. 
Such  persons  do  not  often  neglect  their  opportunities 
for  improvement.  The  young  collegian  may  some¬ 
times  exhaust  his  paternal  bounty,  knowing  or  real¬ 
izing  but  little  of  its  value  ;  but,  the  young  mechanic 
looks  upon  his  time  and  his  means  for  improvement 
as  better  than  money,  inasmuch,  as  on  them  alone  he 
depends  for  means  of  subsistence  and  the  hope  of  fu¬ 
ture  distinction. 

The  author  of  the  following  work  has  received  his 
education  in  the  manner  described — not  under  aca¬ 
demical  supervision  in  classic  halls ;  but  amidst  the 
ponderous  wheels  of  powerful  machinery,  where  he 
was  his  own  teacher.  And,  many  a  time  would  it 
have  saved  him  immense  labor  in  his  pursuits  could 
he  have  had  access  to  a  few  well  made  books  eluci¬ 
dating  the  mysteries  of  his  trade ;  it  would  have 
bouyed  up  his  wearied  spirit  and  led  him  on  to  re¬ 
newed  exertions  in  the  attainment  of  knowledge. 
He  has  spent  years  in  study  which  might  have  been 
saved  for  other  objects.  To  furnish  his  brother  me¬ 
chanics  with  such  a  desideratum,  the  following  pages 
have  been  prepared.  If  the  work  is  not  as  good  as 
it  might  be,  he  trusts  it  is  as  free  from  faults  as  the 
nature  of  the  case  can  well  admit.  He  has  embraced 
a  wide  range,  and  was  obliged,  of  course,  to  be  con¬ 
cise.  The  mechanic  has  neither  the  ability  to  pro- 


PREFACE.  Vll 

cure  voluminous  and  elaborate  treatises ;  nor,  if  pro* 
cured,  the  leisure  to  study  them. 

From  habits  of  intimacy  with  hundreds  and  per¬ 
haps  with  thousands  of  mechanics,  he  is  well  per¬ 
suaded,  that  the  present  effort  to  promote  their  inter¬ 
ests  will  be  duly  appreciated  by  them.  And  there  is 
scarcely  a  laboring  man  in  the  community,  whatever 
be  his  own  particular  trade,  but  what  will  find  much 
in  the  Mechanic’s  Own  Boob  suited  to  his  own  indi¬ 
vidual  wants.  An  examination  of  it  will  convince 
any  one  of  this  fact. 

Mechanics  and  artists  have  occasion  to  be  proud  of 
many  names  among  their  brethren.  Roger  Sherman, 
one  of  the  most  extraordinary  men  of  Connecticut, 
in  earlv  life,  was  an  humble  shoe  maker.  The  Rev. 
Thomas  Baldwin,  D.  D.,  for  many  years,  the  vener¬ 
able  father  as  it  were,  of  the  Baptist  denomination  in 
this  country,  is  said  to  have  been  a  hard  laboring 
blacksmith.  One  of  the  acting  governors  of  the 
State  of  Massachusetts,  now  living  in  affluence  and 
surrounded  by  men  of  eminence,  when  a  boy  was 
poor,  and  an  apprentice  in  a  printing  office.  Other 
cases  of  a  similar  sort  might  be  named  ;  and  the  story 
of  Franklin  is  too  familiar  to  my  readers  to  need  reci¬ 
tal.  The  late  Samuel  Slater  came  to  America  with 
a  few  pounds  only  in  his  pockets  ;  but  he  lived  to  see 
through  his  agency  some  of  the  most  important  rela¬ 
tions  and  interests  of  society  entirely  changed  ;  and 
died  a  man  of  great  wealth.  And  who  can  tell  all 
the  important  results  now  enjoyed  by  the  world,  that 
may  be  traced  back  to  the  untiring  genius  of  Roberf 
Fulton,  once  an  itinerant  painter  ?  Or  to  the  inde- 


PREFACE. 


•  •  • 

nn 

fatigable  Oliver  Evans,  whose  first  studies  were  pur* 
sued  after  the  hours  of  daily  toil,  in  a  wheelwright’s 
shop  by  the  light  of  his  burning  shavings.  And 
Richard  Arkwright,  too,  the  founder  of  cotton  spin¬ 
ning  by  machinery  was  bred  to  the  trade  of  a  barber, 
and&has  obtained  one  of  the  most  endurable  monu¬ 
ments  to  his  genius  the  world  ever  raised.  Indeed, 
it  would  fill  a  volume  to  give  notes  of  all  the  me¬ 
chanics  that  have  acquired  a  praiseworthy  fame. 

In  making  the  above  allusions,  it  may  not  be  in¬ 
appropriate  to  mention  the  names  of  two  other  indi¬ 
viduals  who  have  obtained  an  enviable  reputation. 
The  first  is  Thomas  Blanchard,  extensively  known 
in  the  United  States  for  his  mechanical  skill,  and  now 
employed  in  the  city  of  New  York  endeavoring  to 
perfect  a  new  invention.  He  will  be  remembered  for 
ages  to  come  for  the  benefits  to  society  from  his  un¬ 
tiring  genius.  The  second  is  E.  Burritt,  denomina¬ 
ted,  by  governor  Everett,  the  learned  blacksmith,  a 
resident  of  Worcester,  Massachusetts.  The  appella¬ 
tion  is  a  most  just  one.  He  is  not  thirty  years  of  age, 
and  labors  eight  hours  daily,  at  his  trade,  yet  he  has 
learnt  to  read  fifty  different  languages.  Were  the 
fact  not  supported  by  good  authority,  it  would  be  in¬ 
credible  !  Nor  is  Mr.  Burritt  satisfied  with  his  pre¬ 
sent  attainments ;  he  continues  to  devote  all  his  lei¬ 
sure  time  to  study — that  is,  all  not  spent  in  manual 
labor  and  sleep.  Apparently  he  has  laid  the  founda¬ 
tion  only  of  the  superstructure  to  be  erected  thereon. 
What  an  example  is  his  to  the  young  mechanics  of 
our  country ! 


ARTIST’S  GUIDE, 


AND 

MECHANICS’  OWN  BOOK. 


CHEMISTRY. 


OF  CHEMICAL  NOMENCLATURE. 

From  the  revival  of  learning,  after  the  fall  of  the  Ro¬ 
man  empire,  to  nearly  the  close  of  the  seventeenth  cen¬ 
tury,  Chemistry  was  chiefly  confined  to  those  who  fol¬ 
lowed  it  with  alchemical  views.  Those  persons,  many  of 
whom  knew  that  they  were  deceiving  their  patrons, 
while  others  were  desirous  to  conceal  their  self-delusion, 
or  to  create  admiration  by  the  appearance  of  having 
done  much,  were  anxious  to  give  every  product  of  their 
laboratories  a  mysterious,  extraordinary,  or  unintelligible 
name.  As  they  did  not  act  in  concert,  the  same  prepa¬ 
ration  obtained  very  different  names ;  and,  as  they  were, 
with  few  exceptions,  as  eminent  for  ignorance  as  effron¬ 
tery,  and  carried  on  their  operations  at  random,  they 
examined  but  superficially  the  substances  which  they 
undertook  to  denominate,  and  knew  not  to  what  they 
were  indebted  for  their  leading  properties.  Such  names 
as  horn  moon,  mercury  of  life,  the  wonderful  salt,  the 
salt  with  many  virtues,  form  but  a  small  specimen  of  a 
prodigious  number,  equally  inappropriate  and  ridiculous. 
Hence,  when  the  dreams  of  alchemy  were  broken  by  the 
dawn  of  a  more  enlightened  day— when  men  who  had 
th«  promulgation  of  truth  only  for  their  object,  became 
rbemists,  from  a  persuasion  of  the  advantages  which  the 


10 


CHEMISTRY. 


cultivation  of  that  science  would  afford  to  mankind,  they 
found  it  difficult  to  unravel  the  confusion  which  the 
misnomers  of  their  predecessors  had  created.  In  propor¬ 
tion  as  discoveries  were  multiplied,  the  want  of  a  regular 
and  appropriate  nomenclature  increased,  and  formed  a 
strong  bar  to  the  general  diffusion  of  a  taste  for  chemical 
researches.  A  few  innovations,  which  were  made  by 
single  individuals,  in  order  to  accommodate  the  language 
of  chemistry  to  the  improved  state  of  knowledge,  served 
only  to  show  how  much  was  still  wanted.  It  is  per 
fectly  obvious  that  names  founded  upon  a  mistaken  view 
of  the  properties  of  things,  tend  to  the  propagation  of 
erroneous  opinions,  and  that,  when  a  vast  number  of  sub¬ 
stances  are  designated  at  random,  without  any  connection 
in  names,  although  nearly  related  in  composition,  the 
mere  effort  of  memory  to  recollect  these  names,  will 
exceed  the  effort  which  ought  to  be  required  for  the  ac¬ 
quisition  of  a  science.  Towards  the  close  of  the  last 
century,  therefore,  several  eminent  French  chemists 
determined  to  take  a  comprehensive  view  of  the  subject, 
and  to  remodel  the  whole  system  of  chemical  nomencla¬ 
ture — a  task  which  they  completed  in  1797.  Their 
object  was  to  reject  all  the  old  names  which  were  known 
to  convey  false  ideas,  but  to  preserve  those  which  were 
not  of  this  class,  and  to  which  custom  had  given  a  cur¬ 
rency,  scarcely  and  not  usefully  to  be  checked.  They 
at  the  same  time  introduced  new  terms,  of  appropriate 
derivation ;  and  the  method  of  forming  compound  terms, 
so  as  to  indicate  the  composition  of  compound  bodies, 
was  pointed  out.  This  system  of  nomenclature  possessed 
so  much  merit,  that  the  adoption  of  it  soon  became  gene¬ 
ral  in  France;  and  from  thence,  it  spread  with  great 
rapidity  to  other  countries,  where  it  was  received  either 
entirely,  or  with  such  improvements  as  experience  war¬ 
ranted.  The' objections  which  have  been  urged  against 
it  are  futile;  they  have  chiefly  amounted  to  this, — that 
it  is  not  absolutely  perfect,  and  will,  by  the  progress  of 
discovery,  hereafter  require  to  be  moditied.  On  the  con¬ 
trary,  a  high  eulogium  on  its  value  and  opportune 


CHEMICAL  NOMENCLATURE. 


11 


establishment  is  conveyed  by  the  opinion  of  several  emi¬ 
nent  chemists  that  the  present  state  of  chemistry  could 
not  be  communicated,  much  less  remembered,  by  the 
language  previously  in  use. 

The" following  table  will  exhibit  the  most  important 
changes  of  terms  which  have  been  made,  and  more  par¬ 
ticular  details  will  occur,  as  an  account  of  each  sub« 
stance  gives  occasion : 


Old  names . 

Acetous  Salts,  -  -  - 

Acid  of  vitriol,  phlogisti- 
cated, 

- of  alum  -  -  - 

- of  vitriol  - 

- vitriolic  - 

- of  sulphur  -  - 

- of  nitre,  phlogisti- 

cated, 

- of  nitre,  dephlogisti- 

cated, 

- of  saltpetre  -  - 

- of  sea-salt  -  - 

- marine  -  -  - 

- dephlogisticated  ma¬ 
rine 

- aerial  -  -  - 

- of  chalk  -  - 

- cretaceous 

- calcareous 

- of  charcoal  - 

- mephitic  -  - 

- of  spar  or  fluor 

- sparry  -  - 

- of  borax  -  - 

- of  arsenic 

- of  tungsten 

- - of  wolfram 

- of  molybdina 


New  names 

Acetates. 

Sulphurous  acid. 

Sulphuric  acid. 

Nitrous  acid. 

Nitric  acid. 

Muriatic  acid. 

Oxygenized  muriatic  acid. 

\ 

^Carbonic  acid. 

|  Fluoric  acid 

Boracic  acid. 

Arsenic  acid. 

|  Tungstic  acid. 

Molybdic  acid 


12 


CHEMISTRY 


Old  names 


JVcw  names. 


Acid  of  apples  -  - 

- - of  sugar  •  -  - 

- saccharine  -  - 

- of  wood  sorrel 

■ - of  lemons  -  - 

- of  cream  of  tartar 

- of  benzoin  -  - 

- of  galls  -  -  - 

- of  amber  -  -  - 

- of  ants  ... 

- of  cork  -  -  - 

- of  phosphorus,  phlo- 

gisticated  -  -  - 

- of  phosphorus,  de- 

phlogisticated  -  - 

- of  silk  worms 

- of  fat  - 

- sedative 

- of  lac  -  -  -  * 

- of  milk  --- 

- saccholactic  -  - 

- of  sugar  of  milk 

Air, . 


Malic  acid. 

|  Oxalic  acid. 

Citric  acid. 
Tartaric  acid. 
JBenzoic  acid. 
Gallic  acid. 
Succinic  acid. 
Formic  acid. 
Suberic  acid. 

|  Phosphorus  acid. 

|  Phosphoric  acid. 

Bombic  acid. 
Sebacic  acid. 
Boracic  acid. 
Laccic  acid. 
Lactic  acid. 

|  Mucous  acid. 

Gas.  * 


dephlogisticated 
empyreal  - 
vital  ...  - 

pure  -  -  -  - 

impure  or  vitiated 
burnt  -  -  -  - 

phlogisticated 
inflammable  -  - 

marine  acid  -  - 

dephlogisticated  ma¬ 
rine  acid 


►Oxygen  gas. 


f  Nitrogen  gas,  or  azote,  or 
t  azotic  gas. 

Hydrogen  gas. 

Muriatic  acid  gas. 

)  Oxygenized  muriatic  acid 

)  gas. 


*  The  term  gas  is  now  used  as  a  general  name  for  all  kinds  of 
air,  except  atmospheric  air. 


CHEMICAL  N' 

Old  names. 

Air;  hepatic  -  -  #  -  i 

—  fetid  of  sulphur  - 

—  fixed  - 

— -  solid,  of  Hales 

—  alkaline  -  -  - 

Algaroth,  powder  of  - 

Alkalies,  fixed  -  -  - 

Alkali,  volatile  -  -  - 

_ concrete  volatile 

Alkalies,  caustic  -  - 

Alkalies  effervescent,  or 
not  caustic,  or  aerated, 
or  mild. 

Alkali  vegetable  -  - 

- mineral  -  -  - 

- marine  -  -  - 

- -  prussian  - 

Alum 

Antimony,  crude  -  - 

-  diaphoretic  - 

Aquafoitis  - 

Aqua-regia  -  •  •  ' 

Aqua  ammonia  pura 
Argil,  or  argillaceous  earth, 

Barilla . 

Benzoar  mineral  -  -  - 

Black  lead  - 
Blue,  Prussian  -  -  - 

Borax  - 

Butter  of  antimony  -  - 

Calces,  metallic  -  -  - 

Caustic,  lunar  -  -  - 


MENCLATURE.  ! ° 

New  names. 

Sulphuretted  hydrogen  gas. 

Carbonic  acid  gas. 

Ammoniacal  gas. 

White  oxide  of  antimony  by 
the  muriatic  acid. 

Potash  and  soda. 

Ammonia. 

Carbonate  of  ammonia. 

Pure  alkalies,  or  those  de¬ 
prived  ot  carbonic  acid. 
Alkaline  carbonates,  or  alka 
lies  combined. with  carbo 
nic  acid. 

Potash.* 

Soda. 

Prussiate  of  potass. 

Sulphate  of  alumine  and 
potass. 

Sulphuret  of  antimony. 
White  oxide  of  antimony 
by  the  nitric  acid. 

Nitric  acid  of  commerce. 
Nitro-muriatic  acid. 
Ammonia. 

Alumine. 

Carbonate  of  soda. 

Oxide  of  antimony. 
Hvper-carburet  of  iron. 
Prussiate  of  iron. 

Borate  of  soda. 

Muriate  of  antimony. 
Metallic  oxides. 

Fused  nitrate  of  silver. 


*  The  potash  of  commerce,  when  purified,  is  now  called  potass 

2 


M 


CHEMISTRY. 


Old  names. 


Ceruse . 

m 

Ceruse  ol  antimony  -  - 

Chalk . 

Charcoal,  pine  -  -  - 

Cinnabar  - 

Colthothar  of  vitriol 

Copper,  acetated  -  - 

Copperas,  green  -  -  - 

-  blue  - 

Cream  of  tartar  - 
Earth,  calcareous 

-  aluminous 

-  of  alum  - 

-  siliceous  - 

-  ponderous  -  - 

-  magnesian  -  - 

-  muriatic  - 

Egg,  white  of  ... 
Elastic  gum  - 
Indian  rubber  -  -  - 

Emetic  tartar  -  - 

Essences . 

Ethiops  martial  -  -  - 

- mineral  - 

-  per  se  -  -  - 

Flowers,  metallic  -  - 

- of  sulphur 

Fluors  - 

Glass  of  bismuth  -  - 

Glue  or  jelly  -  -  - 

Glutinous  matter  -  - 

Gypsum . 

He  pars  ..... 


New  names. 

White  oxide  of  lead  by  <be 
acetous  acid. 

White  oxide  of  antimony  by 
precipitation. 

Carbonate  of  lime. 

Carbon. 

Red  sulphuretted  oxide  of 
mercury. 

Red  oxide  of  iron,  by  the 
sulphuric  acid. 

Acetate  of  copper. 

Sulphate  of  iron. 

-  of  copper. 

Supertartrate  of  potass. 

Lime. 


Alumine. 

Silex. 

Barytes. 


Albumen. 

|  Caoutchouc. 

(  Antimoniated  tartrate  o< 
\  potass. 

Volatile  oil. 

Black  oxide  of  iron. 

)  Black  sulphuretted  oxide  ol 
)  mercury. 

Sublimated  metallic  oxides. 

-  sulphur. 

Fl  nates. 

Vitreous  oxide  of  bismuth. 
Gelatine. 

Gluten. 

Sulphate  of  lime. 
Sulphurcts. 


CHEMICAL  NOMENCLATURE. 


15 


Old  names. 

Heat,  latent,  or  matter  of 
heat 

Hermus  mineral  -  - 

Lapis  infernalis  -  -  - 

Leys . - 

Liquor  silicum  -  -  - 

— —  of  flints  -  * 


JVew  names. 


|  Caloric. 

(  Red  sulphuretted  oxide  of 
l  antimony. 

Fused  nitrate  of  silver. 
Solutions  of  alkalies. 

Solutions  of  siliceous  potash. 

(  Litharge,  or  semi- vitreous 
(  oxide  of  lead. 


Litharge 

Liver  of  sulphur,  alkaline  Sulphuret  of  potash. 

Liver  of  sulphur,  calcareous  Sulphuret  of  lime. 

Muriate  of  silver. 

Oxide  of  bismuth  by  the 
nitric  acid. 


Luna  cornea 

Magistery  of  bismuth 

-  of  lead  - 

Magnesia  alba  -  - 

- aerated  - 

- - black  -  - 

Masticot . 

Matter,  amylacious  -  ■ 

Mephitis . 

Minium . 

Mother  waters  -  - 

Nitre . 

Saltpetre  -  -  -  - 

Nitres  . 

Oils,  fat . 

. —  essential  -  - 

—  ethereal  - 
- —  of  tartar  per  deli- 


Precipitated  oxide  of  lead. 

Carbonate  of  magnesia. 

Black  oxide  of  manganese. 
Yellow  oxide  of  lead. 
Fecula,  or  starch. 

Nitrogen. 

Red  oxide  of  lead. 
Deliquescent  saline  residues 

Nitrate  of  potash. 

Nitrates. 

Fixed  oils. 

Volatile  oils. 

i  Solution  of  carbonate  of 
potash. 


quium  3  i 

Phlogiston,  an  imaginary  principle,  adopted  by  Stahl 
and  his  followers,  to  account  for  the  phenomena  of  com¬ 
bustion  Its  existence  having  never  been  proved,  it  has 
no  name  in  modern  science.*  _____ _ 

*  In  general,  the  works  in  which  it  is  used,  may  he  understood 
ny  substituting  the  term  “hydrogen,”  instead  of  it;  and  by 
“  denhlogisticated,”  understanding  free  from  hvdrogen. 


CHEMISTRY. 


16 

Old  names. 

Phosphoric  salts 
Plumbago  - 

Precipitate,  red 

per  se  - 


Principle,  astringent 

■ - tanning 

•  acidifying 


New  names. 
Phosphates. 

Hyper-carburet  of  iron. 

Red  oxide  of  mercury  oy 
the  nitric  acid. 

Red  oxide  ofmercury  by  fire. 
Gallic  acid. 

Tannin. 

Oxygen. 


- inflammable,  identical  with  Phlogiston. 

Pyrites  of  copper  -  -  Sulphuret  of  copper. 


•  martial  - 
factitious 


of  iron. 


-  Redsulphuretedoxideofarsenic. 
The  metal  in  astate  of  purity 

-  Green  oxide  of  copper. 

-  Carbonate  of  iron. 

-  Red  oxide  of  iron. 

-  Muriate  of  ammonia. 

-  Sulphate  of  potass. 

-  Muriate  of  soda. 

febrifuge  of  Sylicius  Muriate  of  potass. 

Phosphate  of  soda  and 
moriia. 

Sulphate  of  soda. 

-  of  magnesia. 


Reulgar  - 
Regulus  of  a  metal 
Rust  of  copper  - 

- of  iron 

Saffron  of  mars  - 
Sal  ammoniac  - 
—  polychrest  - 
Salt,  common  or  sea 


Salt,  fusible  of  urine 

Salt  glaubers  -  - 

- epsom  -  - 

- of  Sorel  -  - 

- of  wormwood 


am- 


vegetable  - 
sedative 


-  Super-oxolate  of  potass. 

-  Carbonate  of  potass. 

-  Tartrate  of  potass. 

-  Boracic  acid. 


- Sthal’s  sulphureous  -  Sulphate  of  potash. 

Selenite . Sulphate  of  lime. 


Spar,  calcareous  -  - 

-  fluor  ...  - 

-  ponderous  -  - 

Spirit,  ardent  -  -  - 

- of  nitre  ... 

- of  nitre,  fuming  - 

- of  salt  -  -  -  - 

- of  sal  ammoniac 


Crystallized  carbonate  of  lime 

-  Filiate  of  lime. 

-  Sulphate  of  barytes. 

-  Alcohol. 

-  Nitric  acid. 

-  Nitrous  acid. 

-  Muriatic  acid. 

-  Ammonia. 


CHEMICAL  NOMENCLATURE. 


17 


Old  names. 

Spirit  of  vitriol  -  ■ 

- of  wine  -  • 

Spiritus  rector  - 

Sublimate,  corrosive 

Sugar  of  lead 


New  names. 


-  -  Sulphuric  acid. 

-  -  Alcohol. 

■  -  Aroma. 

c  Corrosive  muriate  of  mer- 
l  cury. 

_ _ _  _ _  .  -  Acetate  of  lead. 

Sulphur,  alkaline  liver  of  -  Sulphuret  of  potass,  soda,  &c. 

..  r  C  Alkaline  sulphurets  contain- 
-  metallic  liver  of  >  ing  metals. 

Tartar . Super-tartrate  of  potass. 

^  Antimoniated  tartrate  of  po- 
j  tass. 


—  emetic 

vitriolated  - 


Tartars 
Tinctures,  spirituous 

Turbith  mineral 


Verdigris,  or  rust  of  cop-^J 
per 

- exposed  to  the  . 

air  -  -  -  J 

- of  the  shops 


Sulphate  of  potash. 
Tartrates. 

Resins  dissolved  in  alcohol. 
Yellow  oxide  of  mercury  by 
sulphuric  acid. 


)»Green  oxide  of  copper. 


distilled  - 


Vinegar,  distilled 

- -  radical 

Vitriol,  blue  or  roman 


Vitriols 


—  green 

—  martial 

—  white 


Acetate  of  copper  mixed 
)  with  oxide. 
i  Crystallized  acetate  of  cop- 

t  per. 

-  Acetous  acid. 

-  Acetic  acid. 

-  Sulphate  of  copper. 

- of  iron. 

- - of  zinc. 


,  .c.w.o  -  -  Sulphates. 

Water,  acreted  or  acidu-  (  Water  •  impregnated  with 
jated.  I  carbonic  acid. 

Water  impregnated  with 
sulphuretted  hydrogen. 

2*  T> 


hepatic 


18 


CHEMISTRY. 


CHEMICAL  TERMS  EXPLAINED. 


To  the  preceding  view  of  chemical  nomenclature,  the 
following  explanations  of  terms  will  not  perhaps  be  an 
unacceptable  addition. 

Affinity,  (a  proximity  of  relationship.)  The  term  af¬ 
finity  is  used  indifferently  with  attraction.  See  Attrac¬ 
tion. 

Air.  This  term,  till  lately,  was  used  as  the  generic 
name  for  such  invisible  and  exceedingly  rare  fluids  as 
possess  a  very  high  degree  of  elasticity,  and  are  not  con¬ 
densible  into  the  liquid  state  by  any  degree  of  cold 
hitherto  produced;  but,  as  this  term  is  commonly  em¬ 
ployed  to  signify  that  compound  of  aeriform  fluids  which 
constitutes  our  atmosphere,  it  has  been  deemed  advisable 
to  restrict  it  to  this  signification,  and  to  employ  as  the 
generic  term,  the  word  Gas,  for  the  different  kinds  of 
air,  except  what  relates  to  our  atmospheric  compound. 
The  atmosphere  may  be  said,  in  general  terms,  to  consist 
of  oxygen  and  nitrogen ;  but  atmospheric  air,  even  when 
purest,  always  contains  a  small  proportion  of  other  prin 
ciples.  Murray  states  its  exact  composition  as  follows 


By  measure.  By  weight. 


Nitrogen  gas, 

77.5  -  -  - 

75.55 

Oxygen  gas, 

21.0  -  -  - 

23.32 

Aqueous  vapour, 

1.42  -  - 

1.03 

Carbonic  acid  gas, 

.08  -  -  - 

.10 

100.0 

100.0 

Alchemy.  That  branch  of  chemistry  which  relates 
to  the  transmutation  of  metals  into  gold  ;  the  forming  a 
panacea  or  universal  remedy,  an  alcahcst,  or  universal 


CHEMICAL  TERMS  EXPLAINED.  ID 

menstruum,  an  universal  ferment,  and  many  other  absurd- 
•’ties. 

Alchemist.  One  who  practises  the  mystical  art  oi 
alchemy. 

Alkali,  or  ant-acid.  Any  substance  which,  when 
mingled  with  acid,  produces  fermentation.  (See  Alkalies.) 

Alloy.  1.  Where  any  precious  metal  is  mixed  with 
another  of  less  value,  the  assayers  call  the  latter  the 
alloy,  and  do  not  in  general  consider  it  in  any  other  point 
of  view,  than  as  debasing  or  diminishing  the  precious 
metal. 

2.  Philosophical  chemists  have  availed  themselves  of 
this  term,  to  distinguish  all  metallic  compounds  in  gen¬ 
eral.  Thus  brass  is  called  the  alloy  of  copper  and  zinc  ; 
bell-metal,  an  alloy  of  copper  and  tin. 

Every  alloy  is  distinguished  by  the  metal  which  pre¬ 
dominates  in  its  composition,  or  which  gives  it  its  value. 
Thus  English  jewelry,  trinkets,  arc  ranked  under  alloys 
of  gold,  though  most  of  them  deserve  to  be  placed  under 
the  head  of  copper.  When  mercury  is  one  of  the  com¬ 
ponent  metals,  the  alloy  is  called  amalgam.  Thus  we 
have  an  amalgam  of  gold,  silver,  tin,  &c.  Since  there 
are  about  thirty  different  permanent  metals,  independent 
of  those  evanescent  ones  that  constitute  the  basis  of  the 
alkalies  and  earths,  there  ought  to  be  about  870  differ¬ 
ent  species  of  binary  alloys.  But  only  132  species  have 
been  made  and  examined.  Some  metals  have  so  little 
affinity  for  others,  that  as  yet  no  compound  of  them 
has  been  effected,  whatever  pains  have  been  taken. 
Most  of  these  obstacles  to  alloying,  arise  from  the  differ¬ 
ence  in  fusibility  and  volatility.  Yet  a  few  metals,  the 
melting  point  of  which  is  nearly  the  same,  refuse  to 
unite.  It  is  obvious  that  two  bodies  will  not  combine, 
unless  their  affinity  or  reciprocal  attraction  be  stronger 
than  the  cohesive  attraction  of  their  individual  particles. 
To  overcome  this  cohesion  of  the  solid  bodies,  and  ren¬ 
der  affinity  predominant,  they  must  be  penetrated  by 
caloric.  If  one  be  very  difficult  of  fusion,  and  the  other 
very  volatile,  they  will  not  unite  unless  the  reciprocal 


50 


rUHMISTK  Y. 


attraction  be  exceedingly  slrong.  But  if  that  degree  oi 
fusibility  be  almost  the  same,  they  arc  easily  placed  in 
the  circumstances  most  favourable  for  making  an  alloy 
If  we  arc,  therefore,  far  from  knowing  all  the  binary 
alloys  which  arc  possible,  we  are  still  further  removed 
from  knowing  all  the  triple,  quadruple,  &.C.  which  may 
exi  t.  It  must  be  confessed,  moreover,  Uiat  this  depart¬ 
ment  of  chemistry,  has  been  imperfectly  cultivated. 

Analysis.  The  resolution,  by  chemistry,  of  any  matter 
info  its  primary  and  constituent  parts.  The  processes 
and  experiments  which  chemists  have  recourse  to,  are 
vftiy  numerous  and  diversified,  yet  they  may  be  reduced 
t  >  two  species,  which  comprehend  the  whole  art  of 
chemistry.  The  first  is,  analysis ,  or  decomposition  ;  the 
second,  synthesis,  or  composition.  In  analysis,  the  parts 
<>f  which  bodies  are  composed,  are  separated  from  eacli 
other :  thus  if  we  reduce  cinnabar,  which  is  composed  of 
snfphur  and  mercury,  and  exhibit  those  two  bodies  in  a 
separate  state,  we  say  we  have  decomposed  or  analyzed 
cinnabar.  But  if,  on  the  contrary,  several  bodies  be 
mixed  together,  and  a  new  substance  be  produced,  the 
process  is  then  termed  chemical  composition,  or  synthesis . 
thus)  if  by  fusion  and  sublimation,  we  combine  mercury 
wjih  sulphur,  and  form  cinnabar,  the  operation  is  termed 
cb«mical  composition,  or  composition  by  synthesis.  Chem- 
icM  analysis  consists  of  a  great  variety  of  operations. 
In  these  operations,  the  most  extensive  knowledge  of 
such  properties  of  bodies  as  are  already  discovered,  must 
f>‘-  applied,  in  order  to  produce  simplicity  of  effect  and 
c<  rtainty  in  the  results.  Chemical  analysis  can  hardly 
b«*  executed  with  success,  by  one  who  is  not  in  possession 
of  a  considerable  number  of  simple  substances,  in  a  state 
of  great  purity,  many  of  which,  from  their  effects,  are 
veiled  reagents.  The  word  analysis,  is  often  applied  by 
chemists  to  denote  that  series  of  operations  by  which  the 
component  parts  of  bodies  are  determined,  whether  they 
oe  merely  separated  or  exhibited  apart  from  each  other  ; 
or  whether  these  distinctive  properties  be  exhibited  by 
causing  them  to  enter  into  a  new  combination,  without 


CHEMICAL  TERMS  EXPLAINED.  2] 

the  perceptible  intervention  of  a  separate  state;  and  in 
the  chemical  examination  of  bodies,  analysis  or  separa¬ 
tion  can  scarcely  ever  be  effected,  without  synthesis 
taking  place  at  the  same  time. 

Apparatus.  This  term  is  applied  to  the  instruments, 
the  preparation,  and  arrangements,  of  every  thing  ne¬ 
cessary  in  the  performance  of  any  operation,  medical, 
surgical,  or  chemical. 

Assay.  This  operation  consists  in  determining  the 
quantity  of  valuable  or  precious  metal  contained  in  any 
mineral  or  metallic  mixture,  by  analyzing  a  small  part 
thereof.  The  practical  difference  between  the  analysis 
and  assay  of  an  ore,  consists  in  this: — The  analysis,  if 
properly  made,  determines  the  nature  and  qualities  of 
all  the  parts  of  the  compound;  whereas,  the  object  of 
the  assay  consists  in  ascertaining  how  much  of  the  par 
ticular  metal  in  question  may  be  contained  in  a  certain 
determinate  quantity  of  the  material  under  examination. 
Thus,  in  the  assay  of  gold  or  silver,  the  baser  metals  are 
considered  as  of  no  value  or  consequence;  and  the 
problem  to  be  resolved  is  simply,  how  much  of  each  is 
contained  in  the  ingot  or  piece  of  metal  intended  to  be 
assayed. 

Astringent.  That  which,  when  applied  to  the  body, 
renders  the  solids  denser  and  firmer,  by  contracting  their 
fibres,  independently  of  their  living,  or  muscular  power. 
Astringents  thus  serve  to  diminish  excessive  dischargee ; 
and  by  causing  greater  compression  of  the  nervous  fibril- 
lee,  may  lessen  morbid  sensibility  or  irritability.  Hence 
they  may  tend  indirectly  to  restore  the  strength,  when 
impaired  by  these  causes.  The  chief  class  of  these 
articles  are  the  acids,  alum,  lime-water,  chalk,  certain 
preparations  of  copper,  zinc,  iron,  and  lead ;  the  gallic 
acid,  which  is  commonly  found  united  with  the  true 
astringent  principle,  was  long  mistaken  for  it.  Seguin 
first  distinguished  them  ;  and,  from  the  use  of  this  prin¬ 
ciple  in  tanning  skins,  has  given  it  the  name  of  tannin. 
Their  characteristic  differences  are,  the  gallic  acid  forms 


22 


CHEMISTRY. 


a  black  precipitate  with  iron ;  the  astringent  principle 
forms  an  insoluble  compound  with  albumen. 

Atmosphere.  The  elastic  invisible  fluid  which  sur¬ 
rounds  the  earth  to  an  unknown  height,  and  encloses  it 
on  all  sides.  (See  Air.) 

Atoms.  In  the  chemical  combination  of  bodies  with 
each  other,  it  is  observed  that  some  unite  in  all  propor 
tions;  others  in  all  proportions  as  far  as  a  certain  point 
beyond  which  combination  no  longer  takes  place:  there 
are  also  many  examples  in  which  bodies  unite  in  one  pro¬ 
portion  only,  and  others  in  several  proportions;  and  these 
proportions  art)  definite,  and  in  the  intermediate  ones  no 
combination  ensues.  And  it  is  remarkable,  that  when 
one  body  enters  into  combination  with  another,  in  several 
different  proportions,  the  numbers  indicating  the  greater 
proportions  are  exact  simple  multiples  of  that  denoting 
the  smallest  proportion.  In  other  words,  if  the  smallest 
portion  in  which  B.  combines  with  A.  be  denoted  by  10, 
A.  may  combine  with  twice  10  of  B.  or  with  three  times 
10,  and  so  on  ;  but  with  no  intermediate  quantities. 
Fxamples  of  this  kind  have  of  late  so  much  increased  in 
number,  that  the  law  of  simple  multiples  bids  fair  to 
become  universal  with  respect  at  least  to  chemical  com¬ 
pounds,  the  proportions  of  which  are  definite.  By  the 
term  atoms,  we  arc  to  understand  the  smallest  particles 
of  which  bodies  are  composed.  An  atom,  therefore, 
must  be  mechanically  indivisible,  and  of  course  a  fraction 
of  an  atom  cannot  exist,  and  is  a  contradiction  in  terms. 
Whether  the  atoms  of  different  bodies  be  of  the  same 
size,  or  of  different  sizes,  we  have  no  sufficient  evidence 
The  probability  is,  that  the  atoms  of  different  bodies  are 
of  unequal  sizes;  but  it  cannot  be  determined  whether 
their  sizes  bear  any  regular  proportion  to  their  relative 
weights.  We  are  equally  ignorant  of  their  shape;  but 
it  is  probable  they  are  spherical.  Sir  Isaac  Newton 
closes  an  admirable  disquisition  on  the  nature,  laws,  and 
constitution  of  matter,  by  stating  the  great  probability 
that  God  in  the  beginning  formed  matter  into  solid,  mas¬ 
sive,  impenetrable,  moveable  particles  or  atoms,  ol  suck 


CHEMICAL  TEEMS  EXPLAINED. 


<yi 

sizes  and  figures,  and  with  such  other  properties,  and  in 
such  proportion  to  space,  as  most  conduced  to  the  end 
for  which  he  formed  them;  and  that  these  primitive  par¬ 
ticles,  being  absolute  solids,  are  incomparably  harder 
than  any  of  the  bodies  compounded  of  them,  even  so 
hard  as  to  be  incapable  of  wearing  or  breaking  in  pieces, 
nothing  but  Infinite  Power  being  able  to  destroy  what 
Infinite  Power  made  one  in  the  first  creation.  That 
nature  may  be  lasting,  the  changes  of  corporal  things  are 
to  be  attributed  only  to  the  various  separations  and  new 
associations  of  these  permanent  particles;  and  when 
compound  bodies  break,  it  is  not  in  the  midst  of  solid 
particles,  but  where  these  are  laid  together,  and  touch 
only  in  a  few  points. 

Attraction.  The  terms  attraction,  or  affinity,  and 
repulsion,  in  the  language  of  modern  philosophers,  are 
employed  merely  as  the  expression  of  general  facts,  that 
the  masses  or  particles  of  matter  have  a  tendency  to 
approach  and  unite  to,  or  to  recede  from  one  another, 
under  certain  circumstances.  The  term  attraction  is 
used  synonymously  with  affinity. 

All  bodies  have  a  tendency  or  power  to  attract  each 
other,  more  or  less,  and  it  is  this  power  which  is  called 
attraction. 

Attraction  is  mutual:  it  extends  to  indefinite  distances. 
All  bodies,  whatever,  as  well  as  their  component  elemen¬ 
tary  particles,  are  endued  with  it.  It  is  not  annihilated, 
at  however  great,  a  distance  we  suppose  them  to  be 
placed  from  each  other ;  neither  does  it  disappear  though 
they  be  arranged  ever  so  near  each  other. 

The  nature  of  this  reciprocal  attraction,  or  at  least 
the  cause  which  produces  it,  is  altogether  unknown  tc 
us.  Whether  it  be  inherent  in  all  matter,  or  whether 
it  be  the  consequence  of  some  other  agent,  are  questions 
beyond  the  reach  of  human  understanding;  but  its  exis¬ 
tence  is  nevertheless  certain. 

The  instances  of  attraction  which  are  exhibited  by 
the  phenomena  around  us,  are  exceedingly  numerous, 
and  continually  presenting  themselves  to  our  observation. 


CHEMISTRY 


24 

The  effect  of  gravity,  which  causes  the  weight  of  bodies, 
is  so  universal,,  that  we  can  scarcely  form  an  idea  how 
the  universe  could  exist  without  it.  Other  attractions 
such  as  those  of  magnetism  and  electricity,  are  likewise 
observable ;  and  every  experiment  in  chemistry  tends  to 
show,  that  bodies  are  composed  of  various  principles  or 
substances,  which  adhere  to  each  other  with  vaiious 
degrees  of  force,  and  may  be  separated  from  each  other 
by  known  methods. 

The  species  of  attraction  called  chemical  attraction , 
is  also  not  unfrequently  designated  by  the  appellation  of 
the  attraction  of  composition,  or  chemical  affinity.  This 
kind  of  attraction  takes  place  only  between  the  elemen¬ 
tary  particles  of  different  bodies;  and  every  integrant 
part  of  the  compound  which  results  from  its  effects,  dif¬ 
fers  in  its  properties  from  any  of  its  component  parts 
It  is  by  this  change  of  properties  that  chemical  combi 
nation,  or  the  action  of  chemical  attraction,  is  distinguish¬ 
ed  from  mere  mechanical  mixture.  By  mechanical  mix¬ 
ture,  it  is  obvious,  that  gold,  however  minutely  divided, 
could  not  exist  in  every  part  of  a  fluid  lighter  than  itself; 
but  when  the  fluid  has  a  chemical -attraction  for  gold, 
the  solution  is  homogeneous,  and  incapable  of  separation 
by  the  filter,  or  any  other  mechanical  means. 

In  order  to  bring  aflinity  fully  into  action,  it  is  in  gen¬ 
eral  necessary  that  one  or  both  of  the  bodies  presented 
to  each  other,  should  be  in  a  fluid  state ;  or  that  heat 
should  be  applied  to  disunite  the  particles,  by  lessening 
the  attraction  of  cohesion ;  for  mechanical  subdivision  or 
comminution  never  extending  to  the  separation  of  the 
ultimate  particles  of  bodies,  seldom  allows  that  liberty 
of  action,  in  the  exercise  of  which  affinity  appears. 
Instances,  however,  occur,  in  which  two  solids  produce  a 
fluid :  thus,  if  pounded  ice  and  muriate  of  soda  be  mix¬ 
ed  together,  a  fluid  brine  will  be  attained,  unless  the 
temperature,  at  the  time  of  the  experiment,  is  lower 
than  that  at  which  brine  freezes,  and  this  is  thirty-eight 
degrees  below  the  freezing  point  of  water. 

Dr.  Black  discovered  that  whenever  a  body  changes 


CHEMICAL  TERMS  EXPLAINED.  25 

its  state  by  chemical  affinity,  its  temperature  is  changed 
at  the  same  time,  either  lessened  or  increased. 

The  discoveries  of  Sir  H.  Davy,  seem  to  establish  as 
a  fact,  that  no  chemical  affinity. takes  place  between  the 
particles  of  bodies,  unless  they  be  in  an  opposite  electri¬ 
cal  state;  and  that  by  artificially  changing  the  electrical 
state  of  bodies,  their  affinities  may  be  modified  or 
destroyed. 

The  action  of  the  affinity  of  composition,  in  differen 
cases,  has  been  distinguished  in  the  following  manner: 

1.  When  two  principles,  united  together,  are  sepa¬ 
rated  by  means  of  a  third,  we  are  said  to  have  an  ex¬ 
ample  of  simple  affinity.  This  simple  affinity,  Bergman 
called  simple  elective  attraction,  an  expression  still  much 
used  by  chemists. 

2.  When  a  body,  composed  of  two  others,  cannot  be 
destroyed  by  a  third  or  fourth  body  separately  applied, 
vet  is  destroyed  or  decompounded  by  the  action  of  a 
third  and  fourth  bodies,  if  these  be  united  before  they 
are  added  to  it ;  the  example  in  this  case,  and  when  any 
greater  number  of  bodies  are  employed,  is  called  com - 
pound  affinity,  or  compound  elective  attraction. 

3.  When  two  bodies  which  have  no  perceptible  action 
on  each  other,  unite  by  the  addition  of  a  third  body,  the 
example  is  called  intermediate  affinity.  It  is  instanced 
in  the  union  of  oil  and  water,  by  the  means  of  an  alkali. 

Tables  of  elective  attraction  Rave  been  constructed, 
which  are  of  singular  service  in  directing  the  attention 
of  the  chemist  to  the  effects  of  substances  on  each  other  : 
we  shall  advert  to  them  when  we  have  considered  the 
properties  of  substances  themselves. 

Bases.  This  term  is  usually  applied  to  alkalies,  earths, 
and  metallic  oxides,  in  their  relations  to  the  acids  and 
salts.  It  is  sometimes  also  applied  to  the  particular  con¬ 
stituents  of  an  acid  or  oxide,  on  the  supposition  that  the 
substance  combined  with  the  oxygen,  &c.  is  the  basis  of 
the  compound  to  which  it  owes  its  particular  qualities, 
This  notion  seems  unnhilosophical,  as  these  qualities  de* 
3 


CHEMISTUY. 


26 

pend  as  much  on  the  state  of  combination  as  on  the  na 
ture  of  the  constituent. 

Bi.  This  term  is  used  in  anatomy,  botany,  and  chem 
istrv :  in  composition,  it  signifies  twice  or  double. 

Calcareous.  Substances  which  partake  somewhat  of 
the.  nature  and  qualities  of  calx. 

Calcination.  The  fixed  residues  of  such  matters  as 
have  undergone  combustion  arc  called  cinders,  in  com- 
mon  language,  and  calxes,  but  now'  more  commonly  ox¬ 
ides,  by  chemists;  and  the  operation,  when  consideicd 
with  regard  to  these  residues,  is  termed  calcination.  In 
this  general  way,  it  has  likewise  been  applied  to  bodies 
not  really  combustible,  but  only  deprived  of  some  of 
their  principles  by  heat.  Thus  we  hear  of  the  calcina¬ 
tion  of  chalk,  to  convert  it  into  lime  by  driving  off  the 
carbonic  acid  and  water ;  of  gypsum,  or  plaster-stone, 
of  alum,  of  borax,  and  other  saline  bodies,  by  which 
they  arc  deprived  of  their  water  of  crystallization  ;  ot 
bones,  which  lose  their  volatile  parts  by  this  treatment, 
and  of  various  other  bodies.  It  is  also  applied  to  metals, 
in  their  combination  with  oxygen,  by  means  of  heat. 

Caloric.  That  which  produces  the  sensation  of  beat. 
(See  Caloric.) 

Cai'buret.  A  combination  of  charcoal  with  any  other 
substance:  thus  carburetted  hydrogen  is  hydrogen  hold¬ 
ing  carbon  in  solution  ;  carburetted  iron  is  steel,  &.c. 

Caustic.  (To  burn  ;  because  it  always  causes  a  burn¬ 
ing  sensation.)  A  substance  which  always  causes  a  burn¬ 
ing  sensation,  and  has  so  strong  a  tendency  to  combine 
with  organized  substances,  as  to  destroy  their  texture. 

Caick.  A  term  by  which  the  miners  distinguish  the 
opaque  specimens  of  sulphate  of  barytes. 

Cementation.  A  process  in  which  a  body  in  a  solid 
state,  is  surrounded  by  another  in  powder,  and  exposed 
for  some  time  in  a  close  vessel  to  a  degree  of  heat  which 
will  not  fuse  either  of  the  bodies.  Iron  thus  surrounded 
by  charcoal  is  converted  into  steel;  and  copper,  by  ce¬ 
mentation  with  calamine  and  charcoal,  is  converted  into 


CHEMICAL  TERMS  EXPLAINED. 


27 


brass;  green  bottle-glass  is  converted  into  porcelain  by 
cementation  with  sand,  Sic. 

Chlorate.  A  compound  of  chloric  acid  with  a  salifiable 
basis. 

Coagulation.  The  separation  of  the  coagulable  par¬ 
ticles,  contained  in  any  fluid,  from  the  more  thin  and  not 
coagulable  particles:  thus,  when  milk  curdles,  the  co¬ 
agulable ‘particles  form  the  curd;  and  when  acids  are 
thrown  into  any  fluid  containing  coagulable  particles, 
they  form  what  is  called  coagulurn. 

Combination.  The  intimate  union  of  the  particles  of 
different  substances  by  chemical  attraction,  so  as  to  form 
a  compound  possessed  of  new  and  peculiar  properties. 

Combustion.  The  union  of  a  body  with  oxygen  ac¬ 
companied  by  the  evolution  of  light  and  heat ;  therefore 
every  body  which  is  capable  of  forming  this  union,  is 
called  a  combustible.  (See  Combustion.) 

Compound.  The  result  or  effect  of  a  composition  of 
dilferent  things ;  or  that  which  arises  from  them.  It 
stands  opposed  to  simple. 

Concentration.  A  process  by  which  the  watery  part 
of  any  fluid  is  separated,  by  evaporation  ;  or  the  volatil¬ 
izing  of  part  of  the  water  of  fluids,  in  order  to  improve 
their  strength.  The  matter,  therefore,  to  be  concen¬ 
trated,  must  be  of  superior  fixity  to  water.  This  opera¬ 
tion  is  performed  on  some  acids,  particularly  the  sulphu¬ 
ric  and  phosphoric.  It  is  also  employed  in  solutions  of 
alkalies  and  neutral  salts. 

Concretion.  The  condensation  of  any  fluid  substance 
into  a  more  solid  consistence. 

The  growing  together  of  parts  which,  in  a  natural 
state,  are  separate. 

Condensation.  The  thickening  of  any  fluid. 

Congelation.  The  change  of  liquid  bodies,  which 
takes  place  when  they  pass  to  a  solid  state,  by  losing 
the  caloric  which  kept  them  in  a  fluid  state. 

Crystallization.  A  property  by  which  crystallizable 
bodies  tend  to  assume  a  regular  form,  when  placed  favour¬ 
able  to  that  particular  disposition  of  their  particles.  A1 


28 


most  all  minerals  possess  this  property,  but  it  is  most 
eminent  in  saline  substances.  The  circumstances  which 
are  favourable  to  crystallization  of  salts,  and  without 
which  it  cannot  take  place,  arc  two:  J.  Their  particles 
must  be  divided  and  separated  by  a  fluid,  in  order  that 
the  corresponding  faces  of  those  particles  may  meet  and 
unite.  2.  In  order  that  this  union  may  take  place,  the 
fluid  which  separates  the  integrant  parts  of  the  Salt  must 
be  gradually  carried  off,  so  that  it  may  no  longer  divide 
them.  (See  Crystallization.) 

Cupellation.  The  purifying  of  perfect  metals  by 
means  of  an  addition  of  lead,  which,  at  a  due  heat 
becomes  vitrified,  and  promotes  the  vitrification  and  cal¬ 
cination  of  such  imperfect  metals  as  may  be  in  the  mix¬ 
ture,  so  that  these  last  are  carried  off  in  the  fusible 
glass  that  is  formed,  and  the  perfect  metals  are  left 
nearly  pure.  The  name  of  this  operation  is  taken  from 
the  vessels  made  use  of,  which  are  called  cupels. 

Decantation.  The  separation  of  a  fluid  from  the  un¬ 
dissolved  particles  or  solids  which  it  contains.  This  is 
done  by  leaving  the  fluid  at  rest  in  a  conical  vessel;  and 
when  the  foreign  matter  has  deposited  itself  at  the  bot¬ 
tom,  the  fluid  is  gently  poured  off,  in  order  not  to  disturb 
the  sediment.  When  the  matter  deposited  is  light,  and 
apt  to  mix  with  the  fluid,  or  when  the  vessel  containing 
it  cannot  be  conveniently  moved,  a  siphon  is  employed  to 
draw  it  off  A  thick  woollen  thread  steeped  in  the 
liquor,  and  inclining  over  the  edge  of  the  vessel,  makes 
a  very  good  siphon  for  this  purpose. 

Decoction.  A  fluid  holding  in  solution  some  substance 
which  it  has  obtained  by  boiling :  thus  we  say  a  decoc¬ 
tion  of  bark,  &c.  When  the  preparation  is  made  by 
cold  water,  it  is  called  an  infusion. 

Decomposition.  The  substances  of  which  any  com¬ 
pound  body  is  formed,  are  called  its  component  or  con¬ 
stituent  parts;  and  when  these  are  separated  from  each 
other,  the  body  is  said  to  be  decomposed,  or  to  have 
unde: gone  decomposition.  Thus  soap  i-^  compounded  of 
o*t  and  an  alkali;  and  when  the  oil  and  alkali  are  sepa 

>4cd  from  each  rJ.l  r,  the  soap  is  decomposed. 


CHEMICAL  TERMS  EXPLAINED. 


29 


Decrepitation.  The  small  and  successive  explosions 
which  take  place  in  many  chemical  operations,  as  when 
salts  are  exposed  to  heat. 

Deflagration.  A  chemical  term/chiefly  employed  to 
express  the  burning  or  setting  tire- to  any  substance  ;  as 
nitre,  sulphur,  &c. 

Deplegmation.  The  operation  of  rectifying  or  freeing 
spirits  from  their  watery  parts,  or  any  method  by  which 
bodies  are  deprived  of  their  water. 

Dephlogisticated .  A  term  of  the  old  chemistry,  im¬ 
plying,  deprived  of  phlogiston,  or  the  inflammable  prin-' 
ciple. 

Deliquescence.  The  state  of  a  salt  which  becomes 
fluid  by  its  absorption  of  moisture  from  the  atmosphere. 

Desiccation.  (Drying.)  The  expelling  or  evaporating 
of  humid  matter  from  any  substance,  by  means  of  heat. 

Descensus.  Chemists  call  this  a  distillation  by  descent, 
when  the  fire  is  at  the  top  and  round  the  vessel,  the  ori¬ 
fice  of  which  is  at  the  bottom. 

Detonation.  An  explosion  caused  by  a  sudden  expan¬ 
sion  and  combustion  of  certain  substances ;  it  differs  from 
decrepitation  in  being  more  rapid,  and  louder. 

Digestion.  The  slow  action  of  a  solvent  upon  any  sub¬ 
stance,  whether  assisted  by  heat  or  not. 

Distillation.  The  separation  by  heat  of  a  volatile  fluid 
from  other  substances  which  are  fixed ;  or  the  separation 
of  substances  more  or  less  volatile  from  each  other.  (See 
Distillation.) 

Ductility.  A  property  by  which  bodies  are  elongated 
by  repeated  or  continued  pressure.  It  is  peculiar  to 
metals.  Most  authors  confound  the  words  malleability, 
laminability,  and  ductility,  together,  and  use  them  in  a 
loose  indiscriminate  way ;  but  they  are  very  different. 
Malleability  is  the  property  of  a  body  which  enlarges 
c-ne  or  two  of  its  three  dimensions  by  a  blow  or  pressure 
very  suddenly  applied.  Laminability  belongs  to  bodies 
extensible  in  dimension  by  a  gradually  applied  pressure ; 
and  ductility  is  properly  to  be  attributed  to  such  bodies 
as  can  be  rendered  longer  and  thinner  by  drawing  them 
3  * 


CHEMISTRY. 


30 

through  a  hole  of  less  area  than  the  transverse  section 
of  the  body  so  drawn. 

Ebullition.  This  consists  in  the  change  which  a  fluid 
undergoes  from  a  state  of  liquidity  to  that  of  an  elastic 
fluid,  in  consequence  of  the  application  of  heat,  which 
dilates  and  converts  it  into  vapour. 

Effervescence .  The  bubbling  and  noise  produced  by 
the  escape  of  volatile  parts  from  a  fluid,  or  the  agitation 
which  is  produced  by  mixing  substances  together,  which 
cause  the  evolution  of  a  gas. 

Efflorescence.  That  which  takes  place  when  bodies 
spontaneously  become  converted  into  a  dry  powder.  It 
is  almost  always  occasioned  by  the  loss  of  the  water  of 
crystallization  in  saline  bodies. 

Elastic.  Having  the  power  of  returning  to  the  form 
from  which  it  has  been  forced  to  deviate,  or  from  which 
it  is  withheld;  thus  a  blade  of  steel  is  said  to  be  elastic, 
because  if  it  is  bent  to  a  certain  degree,  and  then  let  go, 
it  will  of  itself  return  to  its  former  situation;  the  same 
will  happen  to  the  branch  of  a  tree,  a  piece  of  Indian 
rubber,  &c. 

Eliquation •  An  operation  in  which  a  substance  is 
separated  from  another  which  is  less  fusible,  by  the. 
application  of  a  degree  of  heat  which  will  fuse  only  the 
former;  thus  copper  may  be  separated  from  its  alloy 
with  lead,  with  a  degree  of  heat  which  is  suilicient  only 
to  melt  the  lead. 

Equivalents.  A  term  introduced  into  chemistry  by 
Dr.  Wollaston,  to  express  the  system  of  definite  ratios,  in 
which  the  corpuscular  objects  of  this  science  reciprocally 
unite. 

Essence.  Several  of  the  volatile  or  essential  oils  are 
called  by  this  name. 

Etheteal.  A  term  applied  to  any  highly  rectified  or 
essential  oil,  or  spit  it. 

Evaporation.  A  chemical  process  usually  performed 
by  applying  heat  to  any  compound  substance,  in  ordei 
to  dispel  the  volatile  parts.  It  differs  from  distillation  in 
its  object,  which  chiefly  consists  in  preserving  the  more 


CHEMICAL  TERMS  EXPLAINED. 


31 


fixed  matters,  while  the  volatile  substances  arc  dissipated 
and  lost.  And  the  vessels  arc  accordingly  different : 
evaporation  being  made  in  open  shallow  vessels,  and 
distillation  in  an  apparatus  nearly  closed  from  the  exter¬ 
nal  air. 

The  degree  of  heat  must  be  duly  regulated  in  evapo¬ 
ration.  When  the  fixed  and  more  volatile  parts  do  no 
iiffer  greatly  in  their  tendency  to  fly  off,  the  heat  mus 
be  very  carefully  adjusted ;  but  in  other  cases  this  is  less 
necessary.  As  evaporation  consists  in  the  assumption  of 
the  elastic  form,  its  rapidity  will  be  in  proportion  to  the 
degree  of  heat,  and  the  diminution  of  the  pressure  of 
the  atmosphere. 

Extract.  The  solid  matter  obtained  by  evaporating 
ihc  watery  parts  of  a  decoction  or  infusion. 

Fermentation.  A  slow  motion  of  tlie  intestine  par¬ 
ticles  of  a  mixed  body. 

Filtration.  An  operation  by  which  a  fluid  is  mechan¬ 
ically  separated  from  consistent  particles  mixed  with  it. 
It  does  not  differ  from  straining. 

An  apparatus  fitted  for  this  purpose  is  called  a  filter. 
The  form  of  this  is  various,  according  to  the  intention  of 
the  operator.  A  piece  of  tow,  or  wool,  or  cotton,  stuffed 
into  the  pipe  of  a  funnel,  will  prevent  the  passage  of 
grosser  particles,  and  by  that  means  render  the  fluid 
clearer  Which  comes  through.  Sponge  is  still  more, 
effectual.  A  strip  of  linen  rag  wetted  and  hung  over 
the  side  of  the  vessel  containing  the  fluid,  in  such  a 
manner  that  one  end  of  the  rag  may  be  immersed  in  the 
fluid,  and  the  other  end  may  remain  without,  below  the 
surface,  will  act  as  a  siphon,  and  carry  over  the  clearer 
portion.  Linen  or  woollen  stuffs  may  either  be  fastened 
over  the  mouths  of  proper  vessels,  or  fixed  to  a  frame 
like  a  sieve,  for  the  purpose  of  filtering.  All  these  are 
more  commonly  used  by  cooks  and  apothecaries  than  by 
philosophical  chemists,  who,  for  the  most  part,  use  the 
paper  called  cap  paper,  made  up  without  size. 

As  the  filtration  of  considerable  quantities  of  fluid 
could  not  be  effected  at  once  without  breaking  the  pa- 


.CHEMISTRY. 


per,  it  is  found  requisite  to  use  a  linen  cloth,  upon  which 
the  paper  is  applied  and  supported. 

Precipitates  and  other  pulverulent  matters  are  col¬ 
lected  more  speedily  by  filtration  than  by  subsidence. 
But  there  are  many  chemists  who  disclaim  the  use  of 
this  method,  and  avail  themselves  of  the  latter  only, 
which  is  certainly  more  accurate,  and  liable  to  no  objec¬ 
tion,  where  the  powders  are  such  as  will  admit  of  edul- 
coration  and  drying  in  the  open  air.  __ 

Some  fluids,  as  turbid  water,  may  be  purified  by  filter¬ 
ing  through  sand.  A  large  earthen  funnel,  or  stone  bot¬ 
tle  with  the  bottom  beaten  out,  may  have  its  neck  loosely 
stopped  with  small  stones,  over  which  smaller  may  be 
placed,  supporting  layers  of  gravel  increasing  in  fine¬ 
ness,  and  lastly  covered  with  a  few  inches  of  fine  sand, 
all  thoroughly  cleaned  by  washing.  This  apparatus  is 
superior  to  a  filtering-stone,  as  it  will  clean  water  in 
large  quantities,  and  may  be  readily  renewed  when  the 
passage  is  obstructed,  by7  taking  out  and  washing  the 
upper  stratum  of  sand. 

A  filter  for  corrosive  liquors  may  be  constructed,  oil 
the  same  principles,  of  broken  and  pounded  glass.  (Lrcs 
Chem.  Diet.) 

Fixed.  An  epithet  descriptive  of  such  bodies  as  so  far 
resist  the  action  of  heat  as  not  to  rise  in  vapour.  It  is 
the  opposite  of  volatile;  but  it  must  be  observed,  that 
the  fixity  of  bodies  is  merely  a  relative  term,  as  an  ade¬ 
quate  degree  ot  heat  will  dissipate  all. 

Fluate.  A  compound  of  the  fluoric  acid  with  salifiable 

bases :  thus,  fluate  of  lime,  & c. 

Fluid.  A  fluid  is  that,  the  particles  of  which  so  little 
attract  each  other,  that  when  poured  out,  it  drops,  and 
adapts  itself  in  every  respect  to  the  form  of  the  vessel 

containing  it.  (See  Fluid.) 

Flux.  A  general  term  made  use  of  to  denote  any  sub- 
staiice  or  mixture  added  to  assist  the  fusion  of  metals. 

Fluxion.  A  term  mostly  applied  to  signify  the  change 
of  metals,  or  other  bodies,  from  the  solid  into  a  fluid 
state,  by  the  application  of  heat.  (See  Fusion.) 


CHEMICAL  TERMS  EXPLAINED.  33 

Fulmination.  A  still  more  violent  and  sudden  explo¬ 
sion  than  detonation. 

Fusion.  A  chemical  process,  by  which  bodies  are 
made  to  pass  from  a  solid  to  a  fluid  state  by  means  ot 
the  application  of  heat.  The  chief  objects  susceptible 
of  this  operation  are  salts,  sulphur,  and  metals.  Salta 
are  liable  to  two  kinds  ot  fusion  :  the  one,  which  is  pe¬ 
culiar  to  saline  matters,  is  owing  to  water  contained  in 
them,  and  is  called  aqueous  fusion  ;  the  other,  which 
arises  from  the  heat  alone,  is  known  by  the  name  of 
igneous  fusion.  - 

Gas.  Elastic  fluid  ;  aeriform  fluid.  This  term  is  ap¬ 
plied  to  all  permanently  elastic  fluids,  simple  or  com¬ 
pound,  except  the  atmosphere,  to  which  the  term  air  is 
appropriated.  (See  Gas.) 

Me.  This  terminal  is  aflixed  to  oxygen,  chlorine,  and 
iodine,  when  they  enter  into  combination  with  each 
other,  or  with  simple  combustibles  or  metals,  in  propor¬ 
tions  not  forming  an  acid ;  thus  ox-ide  of  chlorine,  ox-ide 
of  nitrogen,  chlor-ide  of  sulphur,  iod-ide  of  iron. 

Incineration.  The  burning  of  vegetable  or  animal 
substances,  to  obtain  their  ashes,  or  fixed  residue,  which 
is  lixiviated. 

Inflammable.  Chemists  distinguish  by  this  term  such 
substances  as  burn  with  facility,  and  flame  in  an  increase*- 
temperature. 

Infusion.  A  process  that  consists  in  pouring  wate< 
of  any  required  degree  of  temperature  on  such  sub 
stances  as  have  a  loose  texture;  as  thin  bark,  wood  is- 
shavings  or  small  pieces,  leaves,  flowers,  &c.,  and  suffer¬ 
ing  it  to  stand  a  certain  time.  The  liquor  obtained  by 
the  above  process  is  called  an  infusion. 

Iodate.  A  compound  of  iodine  with  oxygen,  and  a 
metallic  basis. 

Iodide.  A  compound  of  iodine  with  a  metal ;  as  Iodide 
vf  pot-assium. 

Lacquer.  A  solution  of  lac  in  alcohol. 

Lactate.  A  definite  compound  formed  by  the  union 
of  the  acid  of  whey,  or  lactic  acid,  with  salifiable  bases ; 
thus,  lactate  of  potassa,  &c. 


C 


CHEM1STILY. 


34 

Leiigation.  The  reduction  of  a  hard  substance,  by 
triture,  to  an  impalpable  powder. 

Liquefaction.  A  term  sometimes  used  synonymously 
with  fusion,  in  others  with  the  word  deliquescence,  and 
in  others  with  the  word  solution. 

Lixiviation.  The  application  of  water  to  the  fixe,-5 
residues  of  bodies,  for  the  purpose  of  extracting  th>* 
saline  parts,  which  dissolve  in  the  water,  and  afterward* 
crystallize  on  evaporation. 

Maceration.  This  term  implies  an  infusion  either  wit} 
or  without  heat,  wherein  the  ingredients  are  intended  ti 
be  almost  wholly  dissolved  in  order  to  extract  theii 
virtues. 

Magistery.  An  obsolete  term  used  by  ancient  chem¬ 
ists  to  signify  a  peculiar  and  secret  method  of  preparing 
any  medicine,  as  it  were  by  a  masterly  process.  The 
term  was  also  long  applied  to  all  precipitates. 

Martial.  Sometimes  used  to  express  preparations  of 
iron,  or  such  as  are  impregnated  therewith  ;  as  the  mar¬ 
tial  regulus  of  antimony,  <fcc. 

Menstruum.  All  liquors  are  so  called  which  arc  used 
as  dissolvents,  or  to  extract  the  virtues  of  ingredients  by 
infusion,  decoction,  &,c. 

Mineralize.  Metallic  substances  are  said  to  be  min¬ 
eralized  when  deprived  of  their  usual  properties  by  com¬ 
bination  with  some  other  substance. 

Mother-water.  When  sea-water,  or  any  other  selec¬ 
tion  containing  various  salts,  is  evaporated,  and  the  crys¬ 
tals  taken  out,  there  always  remains  a  fluid  containing 
deliquescent  salts,  and  the  impurities,  it  present.  This 
is  called  the  mother- water. 

Neutral.  A  term  applied  to  saline  compounds  of  an 
acid  and  an  alkali,  which  are  so  called,  because  they  do 
not  possess  the  characters  of  acid  or  alkaline  salts ;  such 
are  Epsom-salts,  nitre,  and  all  the  compounds  of  alkalies 
with  acids. 

Neutralization.  When  acid  and  alkaline  matter  are 
combined  in  such  proportions,  that  the  compound  does 
not  change  the  colour  of  litmus  or  violets,  they  are  said 
tr>  be  neutralized. 


CHEMICAL  TERMS  EXPLAINED.  35 

Oxidation.  The  process  of  converting  metals  and 
other  substances  into  oxides,  by  combining  with  them  a 
certain  portion  of  oxygen.  It  differs  from  acidification 
in  the  addition  of  oxygen  not  being  sufficient  to  form  an 
acid  with  the  substance  oxidized. 

Oxide.  A  substance  combined  with  oxygen  without 
being  in  the  state  of  an  acid.  Many  substances  are  sus¬ 
ceptible  of  several  stages  of  oxidizementy  on  which  ac¬ 
count  chemists  have  employed  various  terms  to  express 
the  characteristic  distinctions  of  the  several  oxides.  The 
specific  name  is  often  derived  from  some  external  char¬ 
acter,  chiefly  the  colour ;  thus  \ve  have  the  black  and 
red  oxides  of  iron,  and  of  mercury  ;  the  white  oxide  of 
zinc :  but  in  most  instances  the  denominations  proposed 
by  Dr.  Thompson  are  adopted.  When  there  are  several 
oxides  of  the  same  substance,  he  proposes  the  terms 
protoxide,  deutoxide,  tritoxide,  signifying  the  first,  second, 
and  third  stage  of  oxidizement.  Or  if  two  oxides  only 
are  known,  he  proposes  the  appellation  of  protoxide  foi 
that  at  the  minimum,  and  of  peroxide  for  that  at  the 
maximum,  of  oxidation.  The  compounds  of  oxides  anc! 
water  in  which  the  water  exists  in  a  condensed  state, 
are  termed  hydrates,  or  hvdroxures. 

Oxygenation.  This  word  is  often  used  instead  of  oxida¬ 
tion,  and  frequently  confounded  with  it ;  but  it  differs  in 
being  of  more  general  import,  as  every  union  with  oxy¬ 
gen,  whatever  the  product  may  be,  is  an  oxygenation: 
but  oxidation  takes  place  only  when  an  oxide  is  formed. 

Oxyiode.  A  term  applied  by  Sir  H.  Davy  to  the  triple 
compounds  of  oxygen,  iodine,  and  the  metallic  bases. 
Lussac  calls  them  iodates. 

Petrifactions.  Stony  matters  deposited  either  in  the 
way  of  incrustation,  or  within  the  cavities  of  organized 
substances,  are  called  petrifactions.  Calcareous  earth 
being  universally  diffused,  and  capable  of  solution  in 
water,  either  alone  or  bv  the  medium  of  carbonic  acid 
or  sulphuric  acid,  which  are  likewise  very  abundant,  is 
deposited  whenever  the  water  or  the  acid  becomes  dissi¬ 
pated.  In  this  way  we  have  incrustations  of  limestone 


3G 


CHEMISTRY. 


or  of  selenite  in  the  form  of  stalactites  or  dropstones 
from  the  roofs  of  caverns,  and  in  various  other  situations. 

The  most  remarkable  observations  relative  to  petri¬ 
factions  are  thus  given  by  Kerwan  : 

1.  That  those  of  shells  are  found  on,  or  near,  the  sur¬ 
face  of  the  earth  ;  those  of  fish,  deeper ;  those  of  wood, 
deepest.  Shells  in  specie  are  found  in  immense  quanti¬ 
ties  at  considerable  depths. 

2.  That  those  organic  substances  that  resist  putrefac¬ 
tion  most,  are  frequently  found  petrified ;  such  as  shells, 
and  the  harder  species  of  woods:  on  the  contrary,  those 
that  are  aptest  to  putrefy  are  rarely  tound  petrified ; 
as  softer  parts  of  animals,  fish.  &c. 

3.  That  they  are  most  found  in  strata  of  marl,  chalk, 
limestone,  or  clay,  seldom  in  sandstone,  still  more  rarely 
in  gypsum ;  but  never  in  gneiss,  granite,  basalts,  or 
shale;  but  they  sometimes  occur  in  pyrites,  and  ores  of 
iron,  copper,  and  silver,  and  almost  always  consist  of  that 
species  of  earth,  stone,  or  other  mineral  that  surrounds 
them,  sometimes  of  silex,  agate,  or  cornelian. 

4.  That  they  are  found  in  climates  where  their  ori¬ 
ginals  could  not  have  existed. 

5.  That  those  found  in  slate  or  clay  are  compressed 

and  flattened. 

Phlegm.  In  chemistry  this  term  means  the  water  from 
distillation. 

Phlogiston.  The  supposed  general  inflammable  prin¬ 
ciple  of  Stahl,  who  imagined  it  was  pure  fire,  or  the 
matter  of  fire  fixed  in  combustible  bodies,  in  order  to  dis¬ 
tinguish  it  from  fire  in  action,  or  in  a  state  of  liberty. 

Phosphate.  A  salt  formed  by  the  union  of  phosphoric 
acid  with  salifiable  bases;  thus,  phosphate  of  ammonia , 
phosphate  of  lime,  &c. 

Precipitation.  When  two  bodies  arc  united,  for  in 
stance,  an  acid  and  an  oxide,  and  a  third  body  is  added, 
such  as  an  alkali,  which  has  a  greater  affinity  with  the 
acid  than  the  metallic  oxide  has,  the  consequence  is, 
that  the  alkali  combines,  with  the  acid,  and  the  oxide 
thus  deserted  appears  in  a  separate  state,  at  the  bottom 


CHEMICAL  TERMS  EXPLAINED. 


37 


at  a'c  vessel  in  which  the  operation  is  performed.  This 
de  ,»m  position  is  commonly  known  by  the  name  of  pre¬ 
cipitation,  and  the  substance  that  sinks  is  named  a  pre¬ 
cipitate.  The  substance,  by  the  addition  of  which  the 
phenomenon  is  produced,  is  denominated  the  precipitant. 

1  'rinciples.  Substances  or  particles,  which  are  com¬ 
posed  of  two  or  more  el  ments;  thus  water,  gelatine, 
sugar,  fibrine,  &c.,  are  the  principles  of  many  bodies. 
These  principles  are  composed  of  elementary  bodies,  as 
oxygen,  hydrogen,  azote,  &c.,  which  are  undecomposable. 

"Putrefaction .  (To  become  rotten,  to  dissolve.)  Pu¬ 
trid  fermentation.  The  spontaneous  decomposition  of 
animal  and  vegetable  matters,  that  exhale  «  foetid  smell. 
The  solid  and  the  fluid  matters  are  resolved  into  gaseous 
compounds  and  vapours,  which  escape  and  unite  an 
earthy  residuum.  The  requisites  to  this  process  are  : 

1.  A  certain  degree  of  humidity.  2.  The  access  of 
atmospheric  air.  3.  A  certain  degree  of  heat.  Hence 
the  abstraction  of  the  air  and  water,  or  humidity,  b} 
drying,  or  its  fixation  by  cold,  by  salt,  sugar,  spices,  &c., 
will  counteract  the  process  of  putrefaction,  and  favoui 
the  preservation  of  food,  on  which  principle  some  patents 
have  been  obtained. 

Pyrites.  (So  called  because  it  strikes  fire  with  steel.) 
Native  compounds  of  metal  with  sulphur. 

Radical.  This  term  is  applied  to  that  which  is  con¬ 
sidered  as  constituting  the  distinguishing  part  of  an  acid, 
by  its  union  with  the  acidifying  principle  or  oxygen, 
which  is  common  to  all  acids.  Thus  sulphur  is  the  rad¬ 
ical  of  sulphuric  and  sulphurous  acids.  It  is  sometimes 
called  the  base  of  the  acid  ;  but  base  is  a  term  of  more 
extensive  application. 

Rancidity.  The  change  which  oils  undergo  by  ex¬ 
posure  to  air,  which  is  probably  an  effect  analogous  to 
the  oxidation  of  metals. 

Reagent — Test.  A  substance  used  in  chemistry  to 
detect  the  presence  of  other  bodies.  In  the  application 
of  tests,  there  are  two  circumstances  to  attend  to:  viz 
to  avoid  deceitful  appearances,  and  to  have  good  tests. 


CHEMISTRY. 


38 

The  principal  tests  are  the  following: 

1.  Litmus.  The  purple  of  litmus  is  turned  to  red  by 
every  acid  ;  so  that  this  is  the  test  generally  made  use 
of  to  detect  the  excess  of  acid  in  every  fluid.  It  may  be 
used  either  by  dipping  into  the  water  a  piece  of  paper 
stained  with  litmus,  or  by  adding  a  drop  of  the  tincture 
to  the  water  to  be  examined,  and  comparing  its  hue  with 
that  of  an  equal  quantity  of  the  tincture  in  distilled 
water. 

Litmus  already  reddened  by  an  acid,  will  have  its  pur¬ 
ple  restored  by  an  alkali ;  and  thus  it  may  also  be  used 
as  a  test  for  alkalies,  but  it  is  much  less  active  than 
other  direct  alkaline  tests. 

2.  Red  cabbage  has  been  found  by  Watt  to  furnish  as 
delicate  a  test  for  acids  as  litmus,  and  to  be  still  more 
sensible  for  alkalies.  The  natural  colour  of  an  infusion 
of  this  plant  is  blue,  which  is  changed  to  a  red  by  acids, 
and  to  a  green  by  alkalies  in  very  minute  quantities. 

3.  Brazil  wood.  When  chips  of  this  wood  are  infused 
in  warm  water,  they  yield  a  red  liquor,  which  readily 
turns  blue  by  alkalies,  either  caustic  or  carbonated.  It 
is  also  rendered  blue  by  the  carbonated  earths  held  in 
solution  by  carbonic  acid,  so  that  it  is  not  an  unequivocal 
test  of  alkalies  till  the  earthy  carbonates  have  been  pre¬ 
cipitated  by  boiling.  Acids  change  to  yellow  the  natural 
red  of  Brazil  wood,  and  restore  the  red  when  changed 
by  alkalies. 

4.  Violets.  The  delicate  blue  of  the  common  scented 
violet  is  readily  changed  to  green  by  alkalies,  and  this 
affords  a  delicate  test  for  these  substances.  Syrup  of 
violets  is  generally  used  as  it  is  at  hand,  being  used  in 
medicine.  But  a  tincture  of  this  flower  will  answer  as 
well. 

5.  Turmeric.  This  is  a  very  delicate  test  for  alkalies 
and  on  -the  whole,  perhaps,  is  the  best.  The  natural 
colour,  either  in  watery  or  spirituous  infusion,  is  yellow, 
which  is  changed  to  a  brick  or  orange  red  by  alkalies, 
caustic  or  carbonated,  but  not  by  carbonated  earths,  on 
which  account  it  is  preferable  to  Brazil  wood.  The  pure 


CHEMICAL  TERMS  EXPLAINED.  '  39 

earths,  such  as  lime  and  barytes,  produce  the  same 
change. 

G.  Rhubarb.  Infusion  or  tincture  of  rhubarb  under¬ 
goes  a  similar,  change  with  turmeric,  and  is  equally  deli¬ 
cate. 

7.  Sulphuric  acid.  A  drop  or  two  of  concentrated 
sulphuric  acid,  added  to  water  that  contains  carbonic 
acid,  free  or  in  combination,  causes  the  latter  to  escape 
with  a  pretty  brisk  effervescence,  whereby  the  presence 
of  this  gaseous  acid  may  be  detected. 

8.  Nitric  and  oxymuriatic  acid.  A  peculiar  use 
attends  the  use  of  these  acids  in  the  sulphuretted  waters, 
as  the  sulphuretted  hydrogen  is  decomposed  by  them,  its 
hydrogen  absorbed,  and  the  sulphur  separated  in  its  natu¬ 
ral  form. 

0.  Oxalic  acid  and  oxalate  of  ammonia.  These  are 
the  most  delicate  tests  for  lime  and  all  soluble  calcareous 
salts.  Oxalate  of  lime,  though  nearly  insoluble  in  water, 
dissolves  in  a  moderate  quantity  in  its  own  or  any  other 
acid,  and  hence  in  analysis  oxalate  of  ammonia  is  often 
preferred,  as  no  access  of  this  salt  can  redissolve  the  pre¬ 
cipitated  oxalate  of  lime.  On  the  other  hand,  the  am¬ 
monia  should  not  exceed,  otherwise  it  might  give  a  false 
indication. 

10.  Gallic  acid  and  tincture  of  galls.  These  are 
tests  of  iron.  Where  the  iron  is  in  very  minute  quan¬ 
tities,  and  the  water  somewhat  acidulous,  these  tests  do 
not  always  produce  a  precipitate,  but  only  a  slight  red¬ 
dening,  but  their  action  is  much  heightened  by  previously 
adding  a  few  drops  of  any  alkaline  solution. 

11.  Prussiate  of  potassa  or  lime.  The  presence  of 
iron  in  water  is  indicated  by  these  prussiates  causing  a 
blue  precipitate-:  and  if  the  prussiate  of  potassa  is  prop¬ 
erly  prepared,  it  will  only  be  precipitated  by  a  metallic 
salt,  so  that  manganese  and  copper  will  also  be  detected, 
the  former  giving  a  white  precipitate,  the  latter  a  red 
precipitate. 

12.  Lime-water,  is  the  common  test  for  carbonic  acid ; 
it  decomposes  all  the  magnesian  salts,  and  likewise  the 


CHEMISTRY. 


40 

aluminous  salts  ;  it  likewise  produces  a  cloudiness  with 
most  of  the  sulphates,  owing  to  the  formation  of  selenite. 

13.  Ammonia.  This  alkali  when  perfectly  caustic, 
serves  as  a  distinction  between  the  salts  of  lime  and  those 
of  magnesia,  as  it  precipitates  the  earth  from  the  latter 
salts,  but  not  from  the  former.  There  are  two  sources 
of  error  to  be  obviated,  one  is  that  of  carbonic  acid 
being  present  in  the  water,  the  other  is  the  presence  of 
aluminous  salts. 

14.  Carbonated  alkalies.  These  are  used  to  precipi 
tate  all  the  earths ;  where  carbonate  of  potassa  is  used, 
particular  care  should  be  taken  of  its  purity,  as  it  gen¬ 
erally  contains  silex. 

15.  Mu  rioted  alumine.  This  test  is  proposed  by  Mr. 
Kirwan,  to  detect  carbonate  of  magnesia,  which  cannot, 
like  carbonated  lime,  be  separated  by  ebullition,  but 
remains  till  the  whole  liquid  is  evaporated. 

1G.  Barytic  salts.  The  nitrate,  muriate,  and  acetate 
of  barytes  are  all  equally  good  tests  of  sulphuric  acid  in 
any  combination. 

17.  Salts  of  silver.  The  salts  of  silver  are  the  most 
delicate  tests  of  muriatic  acid,  in  any  combination,  pro¬ 
ducing  the  precipitated  luna  cornea.  All  the  salts  of 
silver  likewise  give  a  dark  brown  precipitate  with  sul- 
nhu rated  waters,  which  is  as  delicate  a  test  as  any  we 
possess. 

18.  Salts  of  lead.  The  nitrate  and  acetate  of  lead 
are  the  salts  of  this  metal  employed  as  tests.  They  will 
indicate  the  sulphuric,  muriatic,  and  boracic  acids,  and 
sulphuretted  hydrogen  or  sulphuret  of  potassa. 

19.  Soap.  A  solution  of  soap  in  distilled  water,  or  in 
alcohol,  is  curdled  by  water  containing  any  earthy  or 
metallic  salt. 

20.  Tartaric  acid.  This  acid  is  of  use  in  distinguish¬ 
ing  the  salts  of  potassa  (with  which  it  forms  a  precipitate 
of  cream  of  tartar.)  from  those  of  soda,  from  which  it 
does  not  precipitate.  The  potassa,  however,  must  er»*4 
in  some  quantity  to  be  detected  by  the  test. 

21.  JVitromw'iate  of  platium.  This  sort  is  still  mo. 


CHEMICAL  TERMS  EXPLAINED. 


41 


discriminative  between  potassa  and  the  other  alkalies 
thdn  acid  of  tartar,  and  will  produce  a  precipitate  with 
a  very  weak  solution  of  any  salt  with  potassa. 

22.  Alcohol.  This  most  useful  reagent  is  applicable 
in  a  variety  of  ways  in  analysis.  As  it  dissolves  some 
substances  found  in  fluids,  and  leaves  others  untouched, 
it  is  a  means  of  separating  them  into  two  classes,  which 
saves  considerable  trouble  in  the  further  investigation. 
Those  salts  which  it  does  not  dissolve,  it  precipitates 
from  their  watery  solution,  but  more  or  less  completely 
according  to  the  alt  contained,  and  the  strength  of  the 
alcohol ;  and  as  a  precipitant  it  also  assists  in  many 
decompositions. 

Rectification.  (To  make  clean.)  A  second  distilla¬ 
tion,  in  which  substances  are  purified  by  their  more 
volatile  parts  being  raised  by  heat  carefully  managed  : 
thus,  spirits  of  wine,  ether,  &c.,  are  rectified  by  their 
separation  from  the  less  volatile  and  foreign  matter 
which  altered  or  debased  their  properties. 

Reduction.  When  a  metal  is  converted  into  an  oxide 
by  its  combining  with  oxygen,  it  loses  its  metallic  prop¬ 
erties,  and  assumes  the  appearance  of  an  earth ;  but 
when  the  oxygen  with  which  it  is  combined  is  taken  from 
it,  all  its  properties  as  a  metal  are  recovered;  in  this 
case  the  metal  is  said  to  be  reduced.,  and  the  operation 
by  which  it  is  effected  is  called  reduction.  Revivifica¬ 
tion  is  a  word  used  in  the  same  sense  as  reduction,  but 
is  most  commonly  employed  where  mercury  is  the  metal 
used. 

Residuum,  is  that  part  of  a  body  which  remains  aftei 
the  most  valuable  parts  have  been  separated  by  com¬ 
bustion,  distillation,  or  sublimation. 

Roasting,  a  preliminary  operation,  which  prepares 
mineral  substances  for  undergoing  a  series  of  succeeding 
ones,  dividing  their  constituent  particles,  volatilizing  some 
of  their  principles,  and  thus,  in  a  certain  degree,  altering 
their  nature.  Ores  are  exposed  to  this  process,  with  a 
view  to  separate  the  sulphur  and  the  arsenic  which 
they  contain,  and  to  diminish  the  cohesion  of  their  par 
4  * 


42  CHEMISTRY. 

V 

tides.  Capsules  of  earth  or  iron,  crucibles,  and  roasting 
pots,  are  the  vessels  in  which  it  is  usually  performed  ; 
and  the  ore  is  generally  exposed  to  the  access  of  exter¬ 
nal  air.  Sometimes,  however,  the  operation  is  performed 
in  dose  vessels;  and  two  crucibles,  luted  mouth  to 
mouth,  may  be  employed  on  such  occasions.  Roasting 
is  synonymous  with  torej action  and  ustulation. 

Sal.  (See  Saline.) 

Salifiable.  Having  the  property  of  forming  a  salt. 
The  alkalies,  and  those  earths  and  metallic  oxides  which 
have  the  power  ot  neutralizing  acidity,  entiiely  or  in 
part,  and  producing  salts,  arc  called  salifiable  bases. 

Saline.  (From  sal,  salt.)  Of  a  salt  nature.  The 
number  of  saline  substances  is  very  considerable ;  and 
they  possess  peculiar  characters  by  which  they  are  dis¬ 
tinguished  from  other  substances.  These  characters  are 
founded  on  certain  properties,  which,  it  must  be  con¬ 
fessed,  are  not  accurately  distinctive  of  their  true  nature. 
All  such  substances,  however,  as  possess  several  of  the 
four  following  properties,  are  considered  as  saline : 

1.  A  strong  tendency  to  combination,  or  a  very  strong 
affinity  of  ^composition.  2.  A  greater  or  lesser  degree 
of  sapidity.  3.  A  greater  or  lesser  degree  of  solubility 
in  water.  4.  Perfect  incombustibility. 

Saturation.  Most  bodies  which  have  a  chemical 
affinity  for  each  other,  will  only  unite  in  certain  propor¬ 
tions.  When,  therefore,  a  fluid  has  dissolved  as  much 
of  any  substance  as  it  is  capable  of  dissolving,  it  is  said 
to  have  reached  the  point  of  saturation.  1  hus  water 
will  dissolve  one  quarter  of  its  weight  of  common  salt, 
and  if  more  salt  be  added,  it  will  sink  to  the  bottom  in  a 
solid  state.  Some  fluids  will  dissolve  more  of  certain 
substances  when  hot  than  when  cold.  Thus  water, 
when  hot,  will  dissolve  a  much  larger  quantity  of  nitre 
than  when  cold. 

Sediment.  'The  heavy  parts  of  liquids  which  fall  to 
the  bottom. 

Semi.  In  composition,  this  term  universally  means  half. 

Simple.  This  term  is  applied  very  generally  in  every 


CHEMICAL  TERMS  EXPLAINED.  43 

department  of  nature,  to  designate  that  which  is  not 
compound. 

Solution.  The  dispersion  of  the  particles  of  a  solid 
nody  in  any  fluid,  in  so  equal  a  manner  that  the  compound 
liquor  shall  be  perfectly  and  permanently  clear  and 
transparent.  This  takes  place  when  the  particles  of  the 
fluid  have  an  affinity  or  elective  attraction  for  the  parti¬ 
cles  of  the  solid.  When  solid  particles  are  only  dispersed 
in  a  fluid  by  mechanical  means,  it  is  mixture,  not  solu¬ 
tion,  and  the  compound  usually  opaque  and  muddy. 

Specific  gravity.  The  density,  of  the  matter  of  which 
any  body  is  composed,  compared  to  the  density  of  an¬ 
other  body,  assumed  as  the  standard.  This  standard  is 
pure  distilled  water,  at  the  temperature  of  G0°  F.  To 
determine  the  specific  gravity  of  a  solid,  we  weigh  it, 
first  in  air,  and  then  in  water.  In  the  latter  case,  it 
loses  of  its  weight  a  quantity  precisely  equal  to  the 
weight  of  its  own  bulk  of  water ;  and  hence,  by  com¬ 
paring  this  weight  with  its  total  weight,  we  find  its  spe¬ 
cific  gravity.  The  rule  therefore  is,  divide  the  total 
weight  by  the  loss  of  weight  in  water,  the  quotient  is 
the  specific  gravity.  If  it  be  a  liquid  or  gas,  we  weigh 
it  in  a  glass  or  other  vessel  of  known  capacity;  and  di¬ 
viding  the  weight  by  the  same  bulk  of  water,  the  quo¬ 
tient  is,  as  before,  the  specific  gravity. 

Spirit.  This  name  was  formerly  given  to  all  volatile 
substances  collected  by  distillation.  Three  principal 
kinds  were  distinguished :  inflammable  or  ardent  spirits, 
acid  spirits,  and  alkaline  spirits.  The  word  spirit  is  now 
almost  exclusively  conlincd  to  alcohol. 

Stratification.  An  operation  in  which  bodies  are  placed 
alternately  in  layers,  in  order  that  they  may  act  upon 
each  other  when  heat  is  applied  to  them.  It  is  nearly 
the, same  with  cementation,  but  cementation  is  more  par¬ 
ticularly  applied  to  the  cases  already  noted. 

Sub.  This  term  is  applied  when  a  salifiable  base  is 
predominant  in  a  compound,  there  being  a  deficiency  of 
the  acid ;  a,  subcarbonate  of  potassa,  subcarbonate  oj 
soda. 


44  .  CHEMISTRY. 

Sublimation.  A  process  by  which  volatile  substances 
are  raised  by  heat,  and  again  condensed  in  a  solid  lorm. 
This  process  differs  from  evaporation  only  in  being  con 
fined  to  solid  substances.  It  is  usually  performed  either 
for  the  purpose  of  purifying  certain  substances,  and  dis¬ 
engaging  them  from  extraneous  matters;  or  else  to  re- 
duce^into  vapour,  and  combine,  under  that  form,  princi¬ 
ples  which  would  have  united  with  greater  difficulty  it 
they  had  not  been  brought  to  that  state  ot  extieme 

division.  , 

As  all  fluids  are  volatile  by  heat,  and  consequently 

capable  of  separation,  in  most  cases,  from  fixed  matters, 
so  various  solid  bodies  are  subjected  to  similar  treatment. 
Fluids  are  said  to  distil,  solids  to  sublime;  though  some¬ 
times  both  are  obtained  in  one  and  the  same  operation. 
If  the  subliming  matter  converts  into  a  solid  hard  mass, 
it  is  commonly  called  a  sublimate;  if  into  a  pojvdeiy 
form,  flowers. 

The  principal  subjects  of  this  operation  are,  volatile 
alkaline  salts;  neutral  salts,  composed  of  volatile  alkali 
and  acids,  as  sal  ammonia ;  the  salt  of  amber,  and  flow¬ 
ers  of  benzoin,  mercurial  preparations,  and  sulphur 
Bodies  of  themselves  not  volatile  are  frequently  made  to 
sublime  by  the  mixture  of  volatile  ones ;  thus  iron  is  car- 
vied  over  by  sal  ammoniac  in  the  preparation  ot  the 
flores  martiales,  or  ferrum  ammoniatum. 

The  fumes  of  solid  bodies  in  close  vessels  rise  but  a 
little  way,  arrd  adhere  to  that  part  of  the  vessel  where 

they  concrete.  , 

Super.  This  term  is  applied  to  several  saline  sub- 
stances,  in  which  there  is  an  excess  of  one  of  its  con¬ 
stituents  beyond  what  is  necessary  to  form  the  ordinal y 
compound  ;  as  supersulphate  of  potassa,  supercarbonate 

of  soda,  &c.  * 

Trituration.  The  act  of  reducing  a  solid  body  into  a 
subtile  powder;  as  woods,  barks,  &c.  It  is  performed 
mo-stly  bv  the  rotary  motion  of  a  pestle  in  metallic 
glass,  or  wcdgewood  mortars. 

UreL  The  compounds  of  simple  inflammable  bodies 


CHEMICAL  APPARATUS  DESCRIBED. 


45 


with  each  other,  and  with  metals,  are  commonly  desig¬ 
nated  by  this  word;  as  sulphurei  oi  phosphorus,  carburet 
of  iron,  &c.  The  terms  bisulphuret ,  bisulphate,  &c., 
applied  to  compounds,  imply  that  they  contain  twice  the 
quantity  of  sulphur,  sulphuric  acid,  &c.  existing  in  the 
respective  sulphuret,  sulphate,  &c. 

Viscidity.  Glutinous,  sticky,  like  the  bird  lime. 

Volatilization.  The  reducing  into  vapour,  or  the  aeri 
form  state,  such  substances  as  are  capable  of  assuming  it. 

Way ,  dry.  When  the  chemist  decomposes  substances 
by  the  agency  of  heat,  he  is  said  to  operate  in  the  diy 
way. 

Way,  humid.  When  the  decomposition  is  produced 
by  water  or  other  fluids,  the  effect  is  said  to  be  produced 
in  the  humid  way. 


APPARATUS  DESCRIBED. 


Acetometer.  An  instrument  for  estimating  the  strength 
of  vinegars. 

Adopter.  A  chemical  vessel  with  two  necks  used  to 
combine  retorts  to  the  cucurbits  or  matrasses,  with 
retorts  instead  of  receivers. 

JErometer.  An  instrument  for  making  the  necessary 
corrections  in  pneumatic  experiments  to  ascertain  the 
mean  bulk  of  the  gases. 

Alembic.  A  chemfcal  utensil  made  of  glass,  metal,  oi 
earthenware,  and  adapted  to  receive  volatile  products 
from  retorts.  It  consists  of  a  body  to  which  is  fitted  a 
conical  head,  and  out  of  this  head  descends  latei  ally  a 
beak  to  be  inserted  into  the  receiver. 

Alkalometcr.  The  name  of  an  instrument  for  deter¬ 
mining  the  quantity  of  alkali  in  commercial  potassa  and 
soda. 

'  Alrnometer.  The  name  of  an  instrument  to  measure 
the  quantity  of  exhalation  from  a  humid  suiface  in  a 
given  time. 


CHEMISTRY. 


46 

Barometer.  An  instrument  to  determine  the  weight 
of  air ;  it  is  commonly  called  a  weather-glass. 

Blow-pipe.  A  very  simple  and  useful  instrument 
That  used  by  the  anatomist  is  made  of  silver  or  brass, 
of  the  size  of  a  common  probe,  or  larger,  to  inflate  ves¬ 
sels  and  other  parts. 

The  chemical  blow-pipe  is  made  of  brass,  is  of  about 
one-eighth  of  an  inch  diameter  at  one  end,  and  the  otjier 
tapering  to  a  much  less  size,  with  a  very  small  perfora¬ 
tion  for  the  wind  to  escape.  The  smaller  end  is  levelled 
on  one  side.  Berzelius,  in  a  late  excellent  treatise  on 
the  use  of  the  blow-pipe  in  chemistry  and  mineralogy 
gives  the  preference  to.Ghan’s  construction,  with  an 
additional  bent-beak,  for  a  laboratory  blow-pipe,  and  to 
Wollaston’s  for  a  pocket  instrument. 

Calorimeter.  An  instrument  by  which  the  whole 
quantity  of  absolute  heat  existing  in  a  body  in  chemical 
union  can  be  ascertained. 

Clinometer.  An  instrument  for  measuring  the  dip  of 
mineral  strata. 

Cryophorus.  The  post-bearer,  or  carrier  of  cold  ;  an 
elegant  instrument  invented  by  Dr.  Wollaston,  to  demon¬ 
strate  the  relation  between  evaporation  at  low  tempera¬ 
ture,  and  the  production  of  cold. 

Crucible.  This  vessel  is  employed  in  the  melting  of 
metals,  and  other  operations  of  fusion.  They  are  made, 
for  low  heats,  of  earthenware  or  porcelain,  but  for  strong 
heats,  of  clay  and  sandforclay  and  powdered  plumbago. 
Hessian  and  Dutch  crucibles,  which  are  made  of  refrac¬ 
tory  clay  and  sand,  are  generally  The  most  approved; 
but  modern  chemists  have  an  invaluable  acquisition  in 
platina,  which  is  often  made  into  crucibles,  and  will 
bear,  without  fusion  or  injury,  a  greater  heat  than  any 
other  known  substance. 

Cupel.  A  shallow  earthen  vessel  like  a  cup,  made  of 
phosphate  of  lime,  which  sutlers  the  baser  metals  to  pass 
through  it.  when  exposed  to  heat,  and  retains  the  pure 
metal.  This  process  is  termed  cupellation. 

Cucurbits,  or  matrasses,  arc  glass,  earthen,  or  metallic 


CHEMICAL  APPARATUS  DESCRIBED. 


47 


vessels,  usually  of  an  egg-shape*  and  open  at  the  top 
They  are  used  for  the  purposes  of  digestion,  evapora 
tion,  solution,  &c. 

Digester.  A  strong  and  tight  iron  kettle  or  copper 
furnished  with  a  Valve  of  safety,  in  which  bodies  may 
he  subjected  to  the  vapour  of  water,  alcohol,  or  ether 
at  a  pressure  above  that  of  the  atmosphere. 

Eudiometer.  An  instrument  by  which  the  quantity  of 
oxygen  and  nitrogen  in  atmospherical  air  can  be  ascer¬ 
tained.  Several  methods  have  been  employed,  all 
founded  upon  the  principle  of  decomposing  common  air 
by  means  of  a  body  which  has  a  greater  affinity  for  the 
oxygen. 

Evaporating  vessels.  These  are  made  of  glass,  wood 
metal,  porcelain,  or  Wedgewood’s  ware.  Those  of  the 
last-mentioned  composition  are  very  convenient,  as  the} 
are,  like  glass,  easily  kept  clean,  and  are  not  very  subject* 
to  crack  by  changes  of  temperature.  They  are  gene¬ 
rally  in  the  form  of  shallow  basins,  and  when  the  mattei 
deposited  in  them  would  be  apt  to  burn  to  the  bottom, 
and  be  injured,  if  not  strictly  attended  to,  they  are 
placed  over  the  fire  in  a  vessel  filled  with  sand,  which  is 
then  called  a  sand-bath.  When  even  this  heat  would 
prove  too  great,  the  heat  of  boiling  water  is  used  instead 
of  sand. 

Furnace.  The  furnaces  employed  in  chemical  opera 
tions  are  of  three  kinds:  1.  The  evaporator])  furnace 
which  has  received  its  name  from  its  use:  it  is  employed 
to  reduce  substances  into  vapour  by  means  of  heat,  in 
order  to  separate  the  more  fixed  principles  from  those 
which  are  more  volatile. 

2.  The  reverberatory  furnace,  which  name  it  has 
eceived  from  its  construction,  the  flame  being  prevented 

from  rising.  It  is  appropriated  to  distillation. 

3.  The  forge  furnace.  In  which  the  current  of  air 
is  determined  by  the  bellows. 

Gasometer.  Vessels  constructed  for  the  retention  of 
gas,  and  for  facilitating  the  drawing  of  it  off  as  wanted, 
are  called  gasometers.  Thev  are  much  varied  in  theii 


CHEMISTRY. 


18 

ronstruction  ;  hut  those  on  the  principle  wc  shall  now 
describe,  are  amongst  the  most  simple,  and  answer  per 
feclly  well.  They  are  a  cylindrical  vessel  ot  glass,  or 
japanned  tin-plate,  nearly  filled  with  water,  and  having  a 
tube  in  the  middle  open  at  the  top,  and  branching  at  the 
bottom,  through  the  side  of  the  vessel,  to  which  a  stop¬ 
cock  is  attached.  Within  this  vessel,  there  is  another 
cylindrical  vessel,  generally  of  glass,  open  at  the  bottom, 
w  hich  is  inverted,  and  suspended  by  lines  which  go  ovei 
pullics,  and  have  weights  attached  to  them,  which  hang  on 
the  outside,  to  balance  the  inverted  vessel.  While  the  stop¬ 
cock  at  the  bottom  remains  shut,  if  the  vessel  be  pressed 
downwards,  the  air  inclosed  within  it,  will  remain  within 
in  the  same  situation,  on  the  principle  of  a  diving  bell ; 
but  if  the  cock  be  opened,  and  the  inverted  vessel  be 
pressed  down,  the  air  inclosed  within  it  will  escape 
through  the  cock,  and  if  a  blow-pipe  be  attached  to  this 
cock,  a  stream  of  the  gas  may  be  thrown  upon  lighted 
charcoal,  or  any  other  body.  By  means  of  a  graduated 
rod  on  the  top  of  the  inverted  vessel,  the  quantity  thrown 
out  us  exactly  ascertained  ;  this  rod  being  so  divided  as  to 
express  the  contents  of  the  inner  vessel  in  cubic  feet. 

Goniometer.  An  instrument  for  measuring  the  angles 
of  crystals. 

Hydrometer.  The  best  method  of  weighing  equal 
quantities  of  corrosive  volatile  fluids,  to  determine  their 
specific  gravities,  appears  to  consist  in  enclosing  them  in 
a  bottle  with  a  conical  stopper,  in  the  side  of  which 
stopper  a  fine  mark  is  cut  with  a  file.  The  fluid  being 
poured  into  the  bottle,  it  is  easy  to  put  in  the  stopper 
because  the  redundant  fluid  escapes  through  the  notch 
or  mark,  and  may  be  carefully  wiped  off!  Equal  bulk? 
of  water,  and  other  fluids,  are  weighed  by  this  means  to 
a  great  degree  of  accuracy  :  care  being  taken  to  keep 
the  temperature  as  equal  as  possible,  by  avoiding  any 
contact  of  the  bottle  with  the  hand,  or  otherwise.  The 
bottle  itself  shows  with  much  precision,  by  a  rise  or  fall 
rtf  the  liquor  in  the  notch  of  the  stopper,  whether  such 
change  has  taken  place. 


CHEMICAL  APPARATUS  DESCRIBED. 


49 


The  hydrometer  of  Fahrenheit  consists  of  a  hollow 
ball,  with  a  counterpoise  below,  and  a  very  slender  stem 
above,  terminating  in  a  small  dish.  The  middle,  or  half 
length  of  the  stem,  is  distinguished  by  a  tine  line  across. 
In  this  instrument  every  division  of  the  stem  is  rejected, 
and  it  is  immersed  in  all  experiments,  to  the  middle  of 
the  stem,  by  placing  proper  weights  in  the  little  dish 
above.  Then,  as  the  part  immersed  is  constantly  of  the 
same  mjgnitude,  and  the  whole  weight  of  the  hydrom¬ 
eter  is  known,  this  last  weight  added  to  the  weights  in 
the  dish,  will  be  ecpial  to  the  weight  of  the  fluid  dis¬ 
placed  by  the  instrument,  as  all  writers  on  hydrostatics 
prove.  And  accordingly,  the  specific  gravity  for  the 
common  form  of  tables,  will  be  had  by  the  proportion : 
as  the  whole  weight  of  the  hydrometer  and  its  load, 
when  adjusted  in  distilled  water,  is  to  the  number  1000, 
&c.,  so  is  the  whole  weight  when  adjusted  to  any 
other  fluid  to  the  number  expressing  its  specific  gravity. 

Ilypocleptcium.  A  chemical  vessel  for  separating  li- 
quors,  particularly  the  essential  oil  of  any  vegetable, 
from  the  water;  and  named  because  it  steals,  as  it  were, 
the  water  from  the  oil. 

Hygrometer.  The  state  of  the  atmosphere,  with  re¬ 
spect  to  dryness  or  moisture,  is  measured  by  this  instru¬ 
ment.  It  is  sometimes  called  hygroscope. 

Mortar.  A  sort  of  mould,  a  vessel  to  pound  in. 

Muffles.  In  cupellation,  it  is  necessary  for  the  con¬ 
tents  of  the  cupel  to  be  exposed  to  the  access  of  air ; 
the.  cupel  must  not,  therefore,  be  used  in  a  closed  fur¬ 
nace,  or  be  surrounded  with  fire.  A  kind  of  small  ovens 
are  therefore  employed,  which  are  called  muffles.  They 
are  made  of  the  same  material  as  crucibles,  and  the 
cupel  being  put  into  them,  they  are  exposed  to  the  heat 
of  the  furnace.  They  are  also  used  in  enamelling,  and 
other  operations,  where  heat  is  required,  while  the  con¬ 
tact  of  the  fire  must  be  taken  offi 

Pyrometer.  As  the  common  mercurial  thermometer 
cannot  be  employed  to  ascertain  degrees  of  heat  above 
&00  of  550  degrees  of  Fahrenheit,  it  is  totally  mapplica- 
5  *  I) 


CHEMISTRY. 


50 

ble  to  most  of  the  operations  carried  on  in  furnaces  and 
ovens  :  yet  in  a  variety  of  manufactures  and  chemical 
operations,  success  depends  upon  the  adjustment  of  the 
heat  with  a  degree  of  nicety  which  the  most  experienced 
persons  are  incapable  of  determining  by  mere  observa¬ 
tion.  To  supply  this  desideratum,  Wedgewood  contrived 
an  instrument  called  a  pyrometer,  the  range  of  which 
extends  to  32,000  degrees  of  Fahrenheit’s  scale.  Its 
utility  is  derived  from  the  property  which  clay  has  of 
contracting  in  proportion  to  the  degree  of  heat  to  which 
it  is  exposed.  This  contraction  is  permanent,  and  a  less 
degree  of  heat  than  that  which  the  clay  has  experienced, 
will  not  alter  its  dimensions.  If,  therefore,  a  piece  of 
clay,  of  a  given  bulk,  be  exposed  to  the  heat  of  a  fur¬ 
nace,  it  may  occasionally  be  taken  out,  and  upon  being 
applied  to  a  gauge,  the  degree  of  its  contraction  may  be 
ascertained,  and  consequently  the  greatest  heat  to  which 
it  has  been  exposed,  provided  this  gauge  has  been  grad¬ 
uated  by  previous  experiments.  Wedgewood  constructed 
this  pyrometer  by  duly  availing  himself  of  these  cir¬ 
cumstances. 

The  pyrometic  pieces  of  clay  intended  to  be  used  to 
any  given  scale,  should  be  exactly  of  the  same  composi¬ 
tion,  as  different  clays  contract  in  different  degrees  by 
the  same  heat.  To  guard  against  the  disadvantage  of  a 
difference,  Wedgewood  offered  to  the  Royal  Society  a 
bed  of  Cornish  clay,  sufficiently  extensive  to  furnish  the 
world  for  ages. 

The  gauge  for  measuring  the  diminution  which  the 
pieces  of  clay  suffer  from  the  action  of  tire,  is  made  of 
two  pieces  of  brass,  twenty-iour  inches  long,  with  the 
sides  exactly  plane,  divided  into  inches  and  tenths,  tixco 
live-tenths  asunder  at  one  end,  and  three-tenths  of  an 
inch  at  the  other  end,  upon  a  brass  plate;  arid  the  py¬ 
rometic  pieces  are  made  at  first  so  as  just  to  fit  the  wider 
end.  The  pieces  of  clay  are  generally  made  about  one 
inch  long;  but  if  their  breadth  be  just  equal  to  that  of 
the  wider  end  of  the  gauge,  viz.  five-tenths  of  an  inch, 
their  dimensions  in  other  respects  are  not  material. 


CHEMICAL  APPARATUS  DESCRIBED.  51 

It  is  obvious,  that  in  proportion  to  the  shrinking  of  the 
day  hy  heat,  it  will  slide  farther  and  farther  towards 
the  narrow  end  of  the  converging  scale,  one  side  oi 
which  is  divided  into  tenths  of  an  inch;  and  every  divi 
sion,  of  which  it  contains  240,  answers  to  a  600th  part 
of  the  breadth  of  the  little  piece  of  clay.  One  degree 
of  the  pyrometer  is  equal  to  130  degrees  of  Fahrenheit’s 
scale. 

The  regular  shrinking  of  clay  by  heat,  does  not  com¬ 
mence  at  a  lower  degree  than  a  red  heat  fully  visible  in 
daylight;  and  this  heat  is  equal  to  1077^  degrees  of 
Fahrenheit,  or  about  500  degrees  above  the  point  at 
which  the  mercurial  thermometer  terminates.  It  be¬ 
comes  therefore  desirable  to  measure  the  range  of  tern 
perature  to  which  neither  of  these  instruments  applies; 
but  nothing  has  yet  been  contrived  which  answers  the 
purpose  in  a  simple  manner. 

The  pyrometic  pieces  of  clay  should  be  exposed  as 
nearly  as  possible  to  the  same  heat  as  the  material,  the 
heat  received  by  which  they  are  intended  to  measure. 
For  this  purpose,  they  are  usually  placed  close  to  it,  and 
in  the  same  crucible ;  but  when  the  contents  of  the  cru¬ 
cible  might  adhere  to  them,  they  are  inclosed  in  a  small 
case,  made  of  crucible  clay ;  and  as  they  may  be  re¬ 
duced  in  any  degree,  while  their  breadth  is  retained,  the 
pyrometic  piece  may  generally  be  introduced  without 
difficulty  into  any  but  very  small  crucibles;  and  they 
may  be  disposed  by  the  side  of  very  small  crucibles,  with 
out  much  hazard  of  receiving  their  heat  materially  soon¬ 
er,  or  with  greater  intensity  than  the  contents  of  the 
crucible. 

The  pyrometic  piece  may  be  taken  out  of  the  fire 
during  any  period  of  the  process,  and  instantly  cooled  in 
water,  so  as  to  be  ready  for  measuring  in  the  gauge  in 
the  space  of  a  few  seconds.  It  will  not  crack,  expand, 
contract,  or  sustain  any  other  injury ;  and  may  be  imme¬ 
diately  replaced  in  the  strongest  fire,  to  resume  its  office 
of  indicating  higher  degrees  of  heat  than  what  it  has 
already  been  exposed  to. 


CHEMISTRY. 


52 

The  following  table  will  give  a  better  idea  of  the 
heats  designated  by  the  pyrometer,  than  any  general 
remarks : 


Extremity  of  the  scale  of  the  pyro¬ 
meter  . 

air  furnace,  8 


Fahr.  Wedgw. 


32270°  240° 


an 


common  smith’s 


Greatest  neat  of 
inches  square 
Cast-iron  melts  - 
Greatest  heat  of 

forge . 

Welding  heat  of  iron,  greatest 
Welding  heat  of  iron,  least 
Fine  gold  melts 
Fine  silver  melts 
Swedish  copper  melts 
Brass  melts  -  -  - 

Heat  by  which  enamel  colours 
burnt  on  - 

Red-heat  fully  visible  in  dayligh 
Red-heat  fully  visible  in  dark 
Mercury  boils  -  *  -  - 

Water  boils . 

Vital-heat . 

Water  freezes  - 
Proof  spirit  freezes 


curial  thermometers,  about 


21877 

17977 


1G0 

130 


-  17327 

125 

.  13427 

95 

-  12777 

90 

-  5237 

32 

-  4717 

28 

-  4587 

27 

-  3807 

21 

are 

6 

-  1077 

0 

947 

1 

-  600 

-  212 

GfoVo 

97 

7JUL2- 
*10  0  0 

32 

Q  4  *2 
"fooo 

0 

8foVo 

Iclls  j 

ner- 

o 

• 

• 

®Tooo 

Wedgewood  found  by  analysis,  that  the  clay  of  which 
his  pyrometer  pieces  were  formed,  consisted  ot  two  parts 
of  pure  siliceous  earth,  to  three  parts  of  pure  argillaceous 
or  aluminous  earth. 

The  use  of  the  pyrometer  shows  in  a  remarkable 
manner  the  inaccuracy  of  the  common  mode  of  express¬ 
ing  the  highest  degrees  of  heat  by  estimation.  1  bus  the 
heat  at  which  copper  melts  is  called  a  white  heat,  though 
it  is  only  27°  of  the  pvrometer  ;  the  welding  heat  of  iron, 
or 90°,  is  also  a  white'  heat;  even  130°,  and  upwards,  is 
still  a  white  heat.  These  examples  show  very  clearly 


CHEMICAL  APPARATUS  DESCRIBED. 


53 


that  the  temperature  of  bodies  in  furnaces  is  raised  in  a 
manner  of  which  we  have  no  idea,  unless  the  materials 
subjected  to  it  are  such  as  to  give  us  the  necessary  in¬ 
formation. 

Receiver ,  or  I'ecipienls.  These  vessels  are  usually 
glass  for  small  operations,  for  receiving  the  volatile  pro¬ 
duct  from  a  retort  or  alembic;  they  are  adapted  to  the 
neck  of  the  before-mentioned  apparatus,  and  secured  by 
luting. 

Retorts.  These  are  globular  vessels,  formed  with  a 
long  neck,  and  are  made  of  earthenware,  glass,  or  metal, 
according  to  the  use  for  which  they  are  designed.  They 
are  used  in  distillations,  and  most  frequently  for  those 
which  require  a  degree  of  heat  superior  to  that  of  boil¬ 
ing  water.  The  tube  of  a  retort  is  usually  called  a  beak. 

Glass  retorts  should  be  very  thin,  and  of  a  uniform 
substance  in  every  part ;  otherwise,  from  the  inequality 
of  their  expansion,  they  will  crack  with  the  application 
of  a  very  slight  heat :  they  cannot  also  be  exposed  to 
the  fire,  unless  defended  by  coating,  which  is  generally 
some  earthy  composition.  Cbaftal  particularly  recom¬ 
mends,  for  this  purpose,  fat  earth  which  has  been  suffer¬ 
ed  to  rot  some  hours  in  water  ;  it  must  then  be  kneaded 
with  horse  dung,  and  formed  into  a  soft  paste,  which 
must  be  equally  spread  over  every  part  of  the  retort  to 
be  exposed  to  the  fire.  The  adhesion  of  this  coating  is 
such,  that  should  the  retort  crack  during  the  operation, 
the  distillation  may  still  be  carried  on.  The  retorts  used 
over  a  lamp  are  not  coated. 

Thermometer.  The  thermometer  is  a  well  known 
instrument  for  measuring  the  actual  or  relative  tempera 
ture  of  bodies.  Its  properties  are  dependent  upon  the 
disposition  of  all  bodies  to  acquire  an  equal  degree  of 
sensible  heat  or  cold,  and  on  the  effects  of  heat  in  ex¬ 
panding  some  substances,  the  changes  of  the  dimensions 
of  which  are  examined  by  a  scale  of  equal  divisions. 
Mercury  expands  by  heat,  and  contracts  by  cold,  with 
greater  uniformity  than  any  other  known  lluid ;  it  is, 
therefore,  the  most  proper  and  the  most  commonly  used 
5* 


54  CHEMISTRY. 

for  thermometers,  which  are  constructed  in  the  following 


manner: 

The  first  requisite  is  a  glass  tube,  which  may  be 
obtained  at  the  glass  house,  having  a  bulb  at  one  end, 
which,  together  with  part  of  the  tube,  is  filled  with 
purified  mercury,*  which,  when  introduced  into  the  tube, 
is  boiled  to  expel  the  air  or  moisture  that  might  be  at¬ 
tached  to  it;  and  at  the  moment  it  is  in  ebullition,  the 
extremity  of  the  tube,  being  drawn  to  a  point  by  means 
of  a  blow  pipe,  it  is  hermetically  sealed,  to  prevent  any 
air  from  entering  the  tube.  Or  if  the  scale  be  graduated 
only  to  212°,  the  ball  is  plunged  into  boiling  water,  the 
point  to  which  the  mercury  ascends  accurately  marked. 
For  the  purpose  of  graduating  the  scale,  the  thermome¬ 
ter  is  plunged  into  melting  ice,  and  the  place  where  the 
mercury  stands  marked.  From  the  freezing  to  the  boil¬ 
ing  point  on  Fahrenheit’s  scale,  is  180°,  or  equal  parts; 
and  similar  parts  are  taken  above  and  below,  for  extend¬ 
ing  the  scale. 

Fahrenheit’s  is  the  one  commonly  used  in  this  country, 
and  in  Great  Britain.  The  space  between  the  freezing 


*  Mercury  is  generally  purified  by  distillation ;  but  as  this  ope¬ 
ration  may  not  be  convenient  to  some,  I  shall  mention  Dr.  Priest¬ 
ley’s  mode  of  purifying  it,  which  is  remarkable  for  its  simplicity, 
and  has  an  excellent  effect.  Let  a  strong  10  or  12  ounce  phial, 
with  a  ground  stopper,  be  a  cjuarter  filled  with  mercury  to  bo  puri¬ 
fied  ;  put  in  the  stopper,  hold  the  bottle  inverted  with  both  hands, 
and  shake  it  violently,  by  striking  the  hand  that  supports  it  against 
the  knee.  After  twenty  or  thirty  strokes,  take  out  the  stopper,  and 
blow  into  the  phial  with  a  pair  of  bellows,  to  change  the  air.  If 
the  mercury  is  not  pure,  the  surface  will  become  black  in  a  short 
time  ;  and  if  very  foul,  the  black  coat  will  appear  coagulated.  In¬ 
vert  the  phial,  stopping  it  with  the  finger,  and  let  out  the  running 
mercury.  Put  the  coagulated  part  into  a  cup  by  itself,  and  press 
it  repeatedly  with  the  finger,  so  as  to  get  out  the  mercury  entan¬ 
gled  in  it.  Put  botli  portions  of  mercury  into  the  phial  again,  and 
repeat  the  process  till  no  more  black  powder  separates. 

After  the  mercury  has  been  thus  purified  from  its  admixriire 
with  baser  metals,  it  should  be  boiled  for  about  half  an  hour,  to  free 
it  from  the  moisture  which  it  is  apt  to  contain.  It  may  tht*a  be 
nearly  cooled,  when  it  is  ready  for  the  use  of  thermometers. 


CHEMICAL  APPARATUS  DESCRIBED. 


53 

n  <i  the  boiling  points  is  divided  into  180°,  but  the  scale 
begins  at  that  point  of  temperature  which  is  produced 
bv  a  mixture  of  pounded  ice  and  muriate  of  ammonia, 
or  muriate  of  soda,  which  is  32°  lower,  making  the  whole 
distance  212°. 

The  centigrade  thermometer  is  divided  into  one  hun- 
dred  degrees,  between  the  freezing  and  boiling  points. 
The  freezing  point  is  marked  0,  the  boiling  100°. 

In  Reaumur’s  thermometer,  the  space  between  the 
freezing  and  boiling  points  is  divided  into  eighty  degrees 
The  freezing  point  is  marked  0,  the  boiling  80°. 

The  Russian  thermometer,  commonly  called  Delisle’s, 
begins  its  graduation  at  the  boiling  point,  and  increases 
to  the  freezing.  The  boiling  point  is  marked  0,  the 
freezing  150°. 

Other  fluids,  besides  mercury,  are  sometimes  used, 
such  as  linseed  oil  and  alcohol ;  the  latter  is  used  partic- 
ulaily  for  measuring  low  degrees  of  temperature,  where 
mercury  would  become  solid. 

For  nice  chemical  experiments,  an  air  thermometer  is 
sometimes  used.  The  bulb  of  air  thermometers  is  filled 
with  common  air  only,  and  its  expansion  or  contraction 
is  indicated  by  a  small  drop  of  any  coloured  liquor 
which  is  suspended  within  the  tube,  and  moves  up  and 
down  according  as  the  air  within  the  bulb  or  tube  ex¬ 
pands  and  contracts. 

In  general,  air  thermometers,  however  sensible  to  the 
change  of  temperature,  are  by  no  means  accurate  in 
iheir  indications. 


56 


CHEMISTRY. 


Remarks  on  Apparatus. 

The  list  of  chemical  apparatus  might  still  be  farther 
enlarged,  which  are  of  less  general  application  than 
those  already  noticed,  it  will  be  evident,  that  in  a 
place  where,  as  in  a  laboratory,  several  mechanical 
operations  are  usually  resorted  to,  that  a  laige  strong 
table  or  bench  is  of  considerable  importance.  Conve¬ 
nient  small  tables  or  blocks  of  wood,  should  also  be  at 
Hand,  for  supporting  mortars,  levigating  stones,  an  anvil, 
&c.  A  large  vice,  the  use  of  which  implies  that  oi 
hammers,  rasps,  files,  saws,  and  other  implements  foi 
working  wood  and  metals.  Rods  of  glass,  or  porcelain, 
or  even  clean  straws,  are  used  for  stirring  mixtuies  in 
glasses  and  other  vessels. 

It  is  proper  to  have  a  pair  of  bellows;  shovels,  tongs, 
and  pokers,  for  managing  the  tire,  are  of  course  neces¬ 
sary  ;  and  tongs  of  different  shapes,  for  taking  out  cru¬ 
cibles,  muffles,  &.C.,  from  the  furnace,  which  should  also 
be  at  hand. 

A  plentiful  supply  of  water  should  also  be  at  hand, 
together  with  fuel,  and  many  other  things  which  it  is 
needless  to  allude  to.  Distilled  water  to  be  used  in 
analyses,  and  almost  all  operations  which  are  to  be  con¬ 
ducted  with  exactness. 

In  such  a  place  as  a  laboratory,  where  a  vast  variety 
of  utensils  arc  to  be  arranged,  and  where  the  eve  ought 
to  command  the  situation  of  every  individual  arti<  le,  the 
arrangement  should  be  such  as  to  be  at  once  commodious 
and  easily  maintained.  The  rule,  to  let  every  article 
have  one  place,  and  but  one  place,  is  very  simple,  and 
the  only  sure  method  of  keeping  good  order. 

It  ought  to  be  observed,  that  it  is  injurious  to  the  ad¬ 
vancement  of  chemical  knowledge,  to  give  currency  to 
the  idea,  that  no  discoveries,  or  improvements,  can  be 
made  without  the  aid  of  an  extensive  and  costly  appa¬ 
ratus.  Every  chemist  should  be  a  good  mechanic,  and 
the  resources  of  the  mechanic  who  attends  to  his  pur¬ 
suits  with  his  whole  will,  are  often  sullicient  to  enable 


SUBSTANCES.  57 

him  to  accomplish  very  important  ends,  at  little  expense 
and  by  very  simple  means. 

By  these,  together  with  a  variety  of  other  resources, 
which  are  promptly  suggested  to  the  active  mind,  and 
which  will  be  different  with  persons  in  different  situa¬ 
tions,  a  demonstration  of  all  the  principal  facts  of  chem¬ 
istry  may  be  obtained,  and  new  experiments  carried  into 
execution,  in  some  instances  without  any  real  expense, 
and  in  general  without  much. 


OF  SUBSTANCES. 

Meaning  of  the  term  simple . 

All  substances  in  nature,  when  classed  according  tc 
theii  apparent  or  sensible  properties,  may  be  considered 
either  as  solid,  fluid,  aeriform,  or  ethereal.  But  they 
may  be  distinguished  by  any  of  these  characters,  and 
yet  be  either  simple  or  compound  ;  but  to  make  this  dis- 
tinguishment  in  the  classification  of  substances,  would 
be  incompatible  with  the  design  of  the  present  work  ; 
suffice  it,  therefore,  to  say  in  what  manner  chemists  use 
the  term  simple.  They  do  not  mean  by  the  term  simple, 
that  the  body  to  which  it  is  applied  is  absolutely  known 
to  be  simple,  but  merely  that  it  has  never  been  com¬ 
pounded,  nor  is  known  to  be  capable  of  decomposition. 
Hence,  a  substance  at  this  time  called  simple,  may 
hereafter,  by  more  improved  modes  of  analysis,  be 
proved  a  compound.  What  modern  chemists  call  simple 
bodies,  the  ancient  chemists  call  elements,  a  term  which 
is  vet  sometimes  used. 

The  combination  of  a  substance  with  caloric  or  light, 
is  not  regarded  as  moving  it  out  of  the  class  of  simple 
bodies,  otherwise  we  could  have  nothing  to  denominate 
simple. 


58 


CHEMISTRY. 


OF  LIGHT. 

The  nature  of  light  has  occupied  much  of  the  atten¬ 
tion  of  philosophers,  and  numerous  opinions  have  been 
entertained  concerning'  it.  It  has  sometimes  been  con¬ 
sidered  as  a  distinct  substance,  at  other  times  as  a  qual¬ 
ity  ;  sometimes  as  a  cause,  frequently  as  an  effect;  by 
some  it  has  been  considered  as  a  compound,  by  others  as 
a  simple  substance.  Let  these  considerations  be  as  they 
may,  light  has  an  influence  upon  almost  all  bodies  which 
are  exposed  to  it.  It  is  the  sourde  of  the  colour  of  vege¬ 
tables,  and  in  a  great  measure,  if  not  entirely,  of  their 
odour.  Plants  which  grow  in  darkness  are  devoid  of 
colour,  in  which  case  they  are  said  to  be  etiolated  oi 
blanched.  Gardeners  avail  themselves  of  this  fact  to 
render  vegetables  white  and  tender.  Vegetables  so  sit¬ 
uated  that  the  light  can  only  fall  freely  on  one  side  of 
them,  gradually  turn  to  the  light,  and  chiefly  shoot  out 
in  that  direction.  Some  whose  stems  are  flexible,  follow 
the  course  of  the  sun  during  the  day,  and  always  pre¬ 
sent  the  same  face  towards  him. 

The  back,  fins,  and  other  parts  of  fish  exposed  to  light, 
are  coloured,  but  the  belly,  which  is  deprived  of  light, 
is  always  while. 

The  vegetable  and  animal  productions  of  tropical 
countries,  are  distinguished  by  brighter  colours  than 
those  of  higher  latitudes.  The  cause  of  this  phenome¬ 
non  must  be  referred  to  the  greater  abundance  and  in¬ 
tensity  of  the  light,  upon  the  action  of  which  all  colour 
is  dependent.  The  superior  strength  of  the  perfumes, 
odoriferous  fruits,  and  aromatic  resins,  of  those  countries, 
has  the  same  origin. 

All  metallic  oxides,  but  especially  those  of  mercury 
bismuth,  lead,  silver,  and  gold,  become  of  a  deeper  col 
our  by  exposure  to  the  rays  of  the  sun ;  some  of  them 
become  perfectly  revived,  others  only  partially.  The 
yellow  oxide  of  tungsten,  if  exposed  to  the  light,  loses 
weight  and  becomes  blue.  Green  precipitate  of  iron, 
exposed  to  the  solar  light,  also  becomes  blue. 


LIGHT. 


59 


Light  lias  a  considerable  influence  on  the  crystalliza- 
ion  of  salts,  many  of  which  will  not  crystallize  without 
it.  Camphor  kept  in  glass  bottles,  exposed  to  the  light, 
crystallizes  in  symmetrical  figures  on  that  side  which  is 
turned  towards  the  light ;  and  spirits  of  wine,  water, 
&c.,  rising  by  insensible  evaporation  in  half-filled  ves¬ 
sels,  constantly  attach  themselves  to  the  most  enlightened 
sides  of  the  vessel. 

It  is  not  to  be  supposed  that  these  effects  are  produced 
by  the  mere  contact  of  light ;  on  the  contrary,  we  have 
abundant  proofs  that  light  has  the  power  of  entering 
into  the  composition  of  bodies,  and  of  being  afterwards 
extricated  from  them  without  any  alteration.  A  great 
number  of  substances  become  luminous  after  having 
been  exposed  to  light, — a  property  rendered  obvious  by 
carrying  them  instantly  from  the  light  to  the  dark :  the 
diamond  is  a  body  of  this  kind;  indeed,  if  the  human 
hand  be  thrust  into  a  strong  light,  through  an  aperture 
in  a  perfectly  dark  room,  it  will,  when  drawn  in,  and  the 
aperture  closed,  be  plainly  seen,  although  the  other  hand 
is  totally  invisible. 

Light  is  not  homogeneous:  it  is  composed  of  different 
coloured  rays,  possessing  different  refrangibility.  The 
prismatic  colours  have  been  divided  into  seven,  viz :  red, 
orange,  yellow,  green,  blue,  indigo,  and  violet.  Red  is 
the  least,  and  violet  the  most  refrangible. 

The  rays  of  light  must  be  extremely  rare,  for  they 
cross  each  other  in  all  possible  directions,  without  the 
least  apparent  disturbance. 

The  solar  rays  have  been  divided  into  three  different 
kinds.  1.  Colorific,  or  those  producing  colour.  2.  Cal¬ 
orific,  or  those  producing  heat.  3.  Deoxydizing,  expel¬ 
ling  oxygen,  and  restoring  the  oxides  of  metals  to  their 
metallic  state. 

The  different  sources  from  which  light  is  emitted  in  a 
visible  form,  are :  1.  The  sun  and  fixed  stars.  2.  Com - 

bustion,  which  is  the  act  of  combination  of  the  combus¬ 
tible  with  oxygen  ;  of  course,  the  light  emitted  must 
save  existed  previously,  combined  with  the  combustible 


60 


CHEMISTRY. 


or  with  oxygen.  3.  Heat;  when  the  body  becomes 
luminous  by  being  heated  in  the  fire,  it  is  said  to  be  red 
hot  ;  and  it  is  found  that  all  bodies  that  are  capable  »i 
enduring  the  requisite  degree  of  heat,  without  decompo¬ 
sition  or  volatilization,  begin  to  emit  light  at  the  same 

temperature.  .  .  , 

A  number  of  terms  are  made  use  of  and  explained 
under  the  science  of  optics,  which  might  prove  instruct¬ 
ing. 

OF  CALORIC. 

What  is  denominated  heat,  is  a  sensation  produced  by 
a  substance  called  caloric,  which  penetrates  all  bodies, 
diminishes  the  attraction  of  their  several  parts,  and  uni¬ 
formly  expands  their  dimensions. 

By  means  of  this  powerful  agent,  solid  metals  are 
fused;  liquids  rarified ;  and  almost  all  substances  in  na¬ 
ture  are  converted  into  elastic,  compressible,  or  aeriform 

fluids.  ni.-  c 

It  has  been  asserted  by  Levoiser,  that  all  bodies,  ot 

whatever  kind,  may  exist  in  three  different  states,  solid, 
fluid,  and  aeriform. 

Caloric  is  found  to  exist  under  a  variety  of  forms  or 
modifications.  It  is  said  to  be  free  or  radiant ,  and  is 
commonly  called  heat  or  temperature;  it  is  that  heat 
which  is  perceptible  to  our  senses,  and  affects  the  ther¬ 
mometer,  whatever  be  its  degree,  or  the  source  whence 
it  is  derived. 

Combined  caloric  is  that  w'hich  does  not  affect  the 
thermometer,  and  is  not  perceptible  by  our  senses;  it  is 
retained  in  bodies  by  the  force  of  affinity  or  attraction, 
and  becomes  a  part  of  their  substance. 

Heat  differs  from  caloric  in  this :  one  is  the  cause,  the 
other  the  effect.  The  latter  means  that  which  produces 
heat ;  while  the  former  is  merely  the  sensation. 

Liquids  are  combinations  of  solids  with  a  larger  por¬ 
tion  of  caloric  than  they  naturally  contain. 

Instruments  for  measuring  the  relative  degrees  of  heat, 
are  called  pyrometers,  and  thermometers,  with  suitable 
scales  attached,  indicating  the  degrees. 


CALORIC. 


61 


The  states  in  which  bodies  exist,  admit  of  different 
degrees  of  density  or  consistence,  arising,  for  the  most 
part,  from  the  different  degrees  of  caloric  which  they 
contain.  Solids  are  of  different  degrees  of  density,  from 
that  of  gold  to  that  of  jelly ;  liquids,  from  the  consist¬ 
ence  of  melted  glue,  or  melted  metals,  to  that  of  ether. 
The  different  elastic  fluids  are  susceptible  of  different 
degrees  of  density. 

Bodies  admit  of  different  degrees  of  consistence  with¬ 
out  changing  their  state,  merely  through  the  agency  of 
caloric. 

According  to  late  theory,  caloric  is  composed  of  parti¬ 
cles  perfectly  separate  from  each  other,  every  one  of 
which  moves  with  great  velocity  in  a  certain  direction. 
These  directions  vary  infinitely,  the  result  of  which  is, 
that  there  are  rays  or  lines  of  these  particles,  moving 
with  immense  velocity,  in  every  possible  direction.  Ca¬ 
loric,  then,  is  universally  diffused,  so  that  when  any  por¬ 
tion  of  space  happens  to  be  in  the  neighbourhood  of  an¬ 
other,  which  contains  more  caloric,  the  colder  portion 
receives  a  portion  of  the  calorific  rays  from  the  latter 
sufficient  to  restore  an  equilibrium  of  temperature.  1  his 
radiation  not  only  takes  place  in  iree  space,  but  extends 
also  to  bodies  of  every  kind.  Thus  you  may  suppose 
that  every  body  whatsoever,  is  continually  sending  forth 
rays,  when  the  body  is  surrounded  with  an  elastic  medium, 
or  in  a  vacuum. 

These  rays  are  capable  of  reflection  and  refraction. 

The  manner  in  which  bodies  are  affected  by  rays  pro¬ 
ducing  heat,  differs  in  different  substances,  and  is  very 
much  connected  with  their  colours. 

Bodies  that  absorb  the  most  light  and  of  course  radiate 
heat,  are  heated  the  most  when  exposed  to  solar  or  ter¬ 
restrial  rays. 

Black  bodies  in  general  are  more  heated  than  red,  red 
more  than  green,  green  more  than  yellow,  yellow  more 
than  white. 

All  bodies  are,  in  a  greater  or  less  degree,  conductors 
of  caloric. 

6 


CHEMISTRY. 


62 

Bodies  with  respect  to  caloric  are  divided  into  two 
kinds,  good  and  bad  conductors. 

Metals  and  liquids  are  good  conductors  of  caloric,  but 
silk,  cotton,  wool,  wood,  feathers,  &c.,  are  bad  conductors. 

A  short  rod  of  iron  put  into  the  fire  at  one  end,  will 
very  soon  become  hot  at  the  other  end ;  but  a  piece  of 
wood  or  cane  of  the  same  length,  placed  precisely  in  the 
same  circumstances,  may  be  burnt  to  ashes  at  one  end., 
without  producing  scarcely  a  sensation  of  warmth  at  the 
other. 

The  facility  with  which  bodies  are  cooled  or  heated, 
is  in  proportion  to  their  conducting  power. 

Good  conductors  both  give  and  receive  caloric  quicker, 
and  in  a  given  time  more  abundantly,  than  bad  conduct¬ 
ors,  which  is  the  cause  of  their  feeling  hotter  or  colder ; 
though  they  may  be  in  fact  of  the  same  temperature,  as 
indicated  by  the  thermometer. 

In  general,  the  most  dense  bodies  are  the  best  con¬ 
ductors  of  heat ;  probably,  because  the  denser  the  body, 
the -more  the  number  of  points  that  come  into  contact 
with  caloric. 

Deep  lakes  are  not  frozen  in  winter.  This  is  owing  to 
the  circumstance  of  cold  air  being  constantly  presented 
to  the  surface  of  the  lake,  which  causes  a  portion  of 
water  to  lose  its  temperature,  and  thus  becoming  heavier, 
falls  gradually  to  the  bottom,  while  the  warmer  water 
from  below  ascends,  forming  a  new  surface  in  its  place. 

Caloric  dissolves  water  and  converts  it  into  steam,  by 
insinuating  itself  between  the  particles  which  are  so 
minutely  divided  as  to  become  invisible. 

When  vapour  of  boiling  water  first  issues  from  the 
vessel,  it  is  invisible,  because  it  is  then  completely  dis¬ 
solved  by  caloric.  But  when  it  comes  in  contact  with 
the  cold  air,  it  is  condensed,  in  consequence  of  a  part  of 
the  caloric  being  imparted  to  the  air.  1  he  particles  of 
water  being  in  a  great  measure  deprived  of  their  sol¬ 
vent,  gradually  collect,  and  became  visible  in  the  form 
of  steam,  and  when  further  deprived  of  caloric,  return 
to  their  liquid  state. 


OXYGEN. 


63 


The  atmosphere  dissolves  water  by  means  of  the 
caloric  which  it  contains.  This  is  called  evaporation, 
and  differs  from  vaporization,  which  is  caused  by  culi¬ 
nary  heat. 

The  earth  being  a  great  radiator  of  caloric,  parts  with 
its  heat  more  readily  than  air.  When  the  solar  heat 
declines  and  entirely  ceases  in  the  evening,  the  earth 
rapidly  cools  by  radiating  heat  towards  the  skies;  whilst 
the  air  has  no  means  of  parting  with  its  heat,  but  by 
coming  in  contact  with  the  cool  surface  of  the  earth,  to 
which  it  communicates  its  caloric.  The  solvent  power 
being  thus  reduced,  the  water  is  deposited  in  small  drops 
called  dew. 

OF  OXYGEN 

Oxygen  is  the  name  given  to  the  solid  particles  of 
oxygen  gas,  which  is  a  combination  of  oxygen,  caloric, 
and  light,  'and  is  the  simplest  form  in  which  oxygen  can 
be  obtained.  Oxygen  is  called  the  radical  or  base  of  the 
gas ;  and  the  same  mode  of  expression  is  used  in  other 
cases. 

Oxygen  gas  was  discovered  by  Dr.  Priestley,  on  the 
1st  of  August,  1774.  It  is  invisible,  perfectly  elastic  like 
common  air,  and  possesses  neither  taste  nor  smell.  It  is 
740  times  lighter  than  water.  Its  weight  to  atmospheric 
air,  is  as  1103  to  1000. 

Oxygen  has  never  been  procured  in  an  uncombined 
state.  Its  greatest  purity  is  that  of  gas.  It  is  not  made 
solid  by  any  degree  of  cold,  and  therefore  differs  in  this 
respect  from  vapours  which  may  be  cqndensed  into  a 
liquid,  and  converted  into  a  solid. 

Oxygen  enters  into  chemical  combination  with  a  great 
number  of  substances,  in  which  it  exists  in  a  concrete  or 
solid  state ;  it  is  by  the  application  of  heat,  or  of  acids, 
to  some  of  the  substances  containing  it,  that  it  is  usually 
procured  in  the  form  of  gas. 

Oxygen  gas  may  be  obtained  with  the  greatest  facility 
and  purity,  from  hyper-oxy muriate  of  potass.  A  small 
retort  must  be  partly  filled  with  this  salt,  and  exposed 


) 


64 


CHEMISTRY. 


to  the  heat  of  a  lamp;  the  salt  melts,  and  oxygen  is 
extricated  in  abundance,  as  it  is  held  by  this  singular 
substance  in  a  state  of  great  concentration,  and  by  a 

very  weak  affinity.  f 

Ingenhouz  obtained  from  four  ounces  of  nitrate  cl 
potass,  melted  with  a  little  slacked  lime,  3000  cubic 
inches  of  this  gas.  Let  any  quantity  of  this  salt  be  put 
into  an  earthern  or  iron  retort,  to  the  extremity  ol  which 
is  adapted  a  bent  tube,  terminating  in  the  pneumati 
trough.  The  retort  must  be  gradually  made  red-hot 
when  the  oxygen  gas  will  be  rapidly  disengaged,  and 

will  be  very  pure.  . 

When  considerable  quantities  of  oxygen  are  required, 
the  black  oxide  of  manganese  is  most  frequently  used, 
as  it  is  the  cheapest  article  that  can  be  employed,  and 
supplies  the  gas  in  a  good  degree  of  purity.  1  he 
manganese  is  put  into  a  retort,  which  is  made  red-hot, 
and  the  gas  is  collected  by  the  pneumatic  apparatus,  as 
in  using  nitrate  of  potass.  One  pound  o(  the  best 
manganese  will  yield  upwards  of  1400  cubic  inches  of 
the  gas.  The  retort  is  easily  cleared  of  the  manganese 
when  the  experiment  is  ended  ;  and  if  the  manganese 
that  has  once  been  used,  be  exposed  to  the  air  for  some 
time,  it  will  serve  again;  but  the  cheapness  ot  the  arti¬ 
cle  renders  this  of  little  consequence. 

Red  oxide  of  mercury,  and  of  lead,  yield  oxygen  iu 


the  same  manner  as  manganese.  ,  , 

Oxygen  gas  is  the  only  one  that  can  be  breathed  by 
animals  for  any  length  of  time  with  impunity,  ihe 
power  of  atmospheric  air  in  supporting  respiration,  is 

owing  to  the  oxygen.  .  .  ,  , 

In  respiration,  a  quantity  of  atmospheric  air  is  taken 

into  the  lungs ;  the  oxygen  disappears,  and  a  quantity  ot 
carbonic  acid  gas,  equal  in  bulk,  is  tormed  in  its  stead. 
A  reciprocal  influence  is  exerted  between  this  aerial 
fluid  and  the  circulating  blood ;  and  the  continuance  ot 
life  is  dependent  upon  the  due  exercise  of  this  influence, 
which  appears  by  the  conversion  of  oxygen  into  carbonic 

acid. 


OXYGEN.  65 

Animals  confined  in  oxygen  gas  will  live  four  or  five 
limes  longer  than  when  confined  in  atmospheric  air. 

It  may  be  breathed  by  men  for  some  time,  without 
producing  any  other  effect  than  a  sensation  of  warmth 
and  slight  stricture  of  the  chest. 

Oxygen  forms  about  22  per  cent,  of  the  atmospheric 
air :  the  rest  is  nitrogen  or  azotic  gas,  except  a  smal 
quantity  of  carbonic  acid. 

Oxygen  combines  with  all  the  metals ;  and  in  that 
state,  they  are  called  metallic  oxides,  depriving  them  of 
their  metallic  lustre,  and  giving  them  an  earthy  or  rusty 
appearance. 

Some  of  the  metals  become  oxidized,  or  are  rusted  by 
mere  exposure  to  the  damp  atmosphere. 

Iron,  exposed  to  the  weather,  soon  becomes  rusty,  by 
attracting  oxygen  from  the  air  or  water. 

All  oxides  are  heavier  than  the  metal,  in  proportion 
to  the  quantity  of  oxygen  with  which  they  are  com¬ 
bined. 

Many  of  the  metals  are  capable  of  combining  with 
different  proportions  of  oxygen.  Those  with  one  propor¬ 
tion  are  called  protoxides ;  of  two,  deutoxides ;  those  of 
three,  tritoxides . 

A  metal  combined  with  the  greatest  proportions  of 
oxygen  is  called  peroxide. 

Oxygen  has  a  powerful  effect  on  vegetable  colours, 
producing  (he  various  tints  of  shade  which  we  behold  in 
this  department  of  nature. 

Yarn,  when  taken  from  the  blue  vat,  is  green,  but,  on 
exposure  to  the  air,  it  imbibes  oxygen,  and  is  changed  to 
a  blue. 

It  is  well  known  to  the  dyers,  that  they  cannot  produce 
a  good  black  without  exposing  their  stuffs  to  the  air. 

Vegetable  colours  fade  on  exposure  to  the  sun,  which 
is  probably  owing  to  this  principle  :  the  oxygen  which 
pieviously  existed  in  the  colouring  matter  in  a  solid  form, 
is  rendered  aeriform  by  the  rays  of  the  sun,  and  is  evolved 
in  the  form  of  gas. 


I 


CHEMISTRY. 


r»6 


OF  NITROGEN. 

Nitrogen  is  the  basis  of  the  nitric  add.  It  exhibits 
(self  in  its  simplest  state  as  a  gas.  It  was  formerly  called 
azote,  because  it  was  destructive  to  animal  lite. 

Nitrogen  gas  is  most  easily  described  by  including 
many  ot  its  negative  qualities.  It  has  no  taste  ;  it  neither 
reddens  vegetable  blue  colours,  nor  precipitates  lime- 
water;  it  is  not  absorbed  by  water.  It  unites  to  oxygen 
in  several  proportions;  it  also  unites  to  hydrogen. 
Though  incapable  of  being  breathed  above  its  base, 
nitrogen  is  a  component  portion  of  all  animal  substances 
It  is  lighter  than  oxygen.  Dr.  Black  found  that  a  vessel 
of  1000  cubical  inches,  which  will  contain  315  troy  grains 
of  atmospheric  air,  will  contain  335  of  oxygen  gas,  but 
only  297  of  nitrogen  gas. 

Nitrogen  gas  may  be  variously  obtained.  If  the  oxy¬ 
gen  be  extracted  from  the  atmospheric  air,  this  substance 
will  remain,  and  will  generally  be  very  pure,  unless  the 
oxygen  has  been  extracted  by  respiration.  If  iron  filings 
and  sulphur,  moistened  with  water,  be  put  into  a  jar 
containing  atmospherical  air,  this  gas  will,  in  a  day  or 
two  be  all  the  air  that  remains  in  the  jar,  as  the  oxygen 
will  be  absorbed  by  the  iron  and  sulphur.  Phosphorus, 
or  sulphuret  of  lime  or  potass,  inclosed  with  common  air 
in  a  jar,  will  produce  a  similar  effect. 

Nitrogen  gas  mav  likewise  be  obtained  from  animal 
substances.  For  this  purpose,  put  some  small  pieces  of 
lean  muscular  flesh  into  a  retort,  and  cover  them  with 
weak  nitric  acid.  The  heat  of  a  lamp  will  extricate 
the  gas,  which  may  be  collected  by  the  pneumatic 
apparatus. 

It  has  been  conjectured  that  nitrogen  is  not  a  simple 
substance,  but  no  experiments  have  decisively  proved  this. 

Atmospherical  air  contains  78  parts  in  the  100,  by 
measure  of  nitrogen  gas ;  the  22  remaining  parts,  or 
oxygen,  being  thus  largely  diluted,  becomes  proportion¬ 
ately  less  intense  in  its  stimulating  effects,  and  tit  for  the 
purposes  of  life,  the  length  of  which  is  increased  by  tbit 


HYDROGEN. 


07 


source  of  moderation  in  its  course.  By  mixing  pure 
nitrogen  gas  and  oxygen  gas  in  the  proportions  just  men- 
ioned,  a  gas  having  all  the  properties  of  atmospherical 
air  is  the  result. 

Though  animal  life  cannot  be  sustained  for  a  moment 
by  nitrogen  gas,  yet  it  is  congenial  to  vegetables,  and 
appears  to  be  a  part  of  their  food  ;  they  derive  it  from 
its  combinations  with  oxygen  in  atmospherical  air. 

OF  HYDROGEN. 

The  third  and  last  substance,  which,  in  its  simplest 
form,  can  only  be  obtained  in  an  aerial  state,  is  called 
hydrogen.  This  gas  has  long  been  generally  known  by 
the  name  of  inflammable  air  ;  it  is  the  gas  which  miners 
call  fire  damp. 

Hydrogen  with  oxygen  forms  water;  and  it  is  by  the 
decomposition  of  water  that  chemists  obtain  it  in  the 
greatest  abundance  and  purity.  For  this  purpose,  iron 
Jilings  or  turnings,  or  granulated  zinc,  are  put  into  a 
retort,  and  covered  with  sulphuric  acid  diluted  with  four 
times  its  weight  of  water.  A  violent  effervescence 
ensues,  a  large  quantity  of  gas  is  evolved,  and  issuing 
from  the  retort,  is  collected  in  the  usual  manner  by  the 
pneumatic  apparatus.  In  this  experiment,  the  acid  is 
not  decomposed ;  it  is  the  oxygen  of  the  water  with 
which  the  acid  is  diluted,  that  seizes  upon  and  oxidizes 
the  metal,  and  the  hydrogen  in  the  same  portion  of 
water  being  then  disengaged,  passes  over  in  the  state  of 
gas.  The  hydrogen  obtained  by  using  zinc  is  the  purest ; 
that  obtained  by  using  iron  generally  containing  some 
carbon. 

The  process  just  described  is  the  readiest  for  obtaining 
this  gas,  but  it  is  evolved  in  every  instance  in  which 
metais  are  tarnished  or  rusted  by  moisture,  and  it  may 
be  obtained  in  great  quantities,  by  causing  the  vapour 
of  water  to  pass  through  an  iron  tube,  or  through  a  tube 
of  any  kind,  containing  a  coil  of  iron  wire,  heated  to 
ignition.  The  operation  is  generally  conducted  by  the 


CHEMISTRY. 


68 

use  of  a  furnace,  provided  with  small  holes  opposite  each 
other,  to  admit  the  tube  to  pass  through  it. 

Hydrogen,  like  oxvgen  and  nitrogen,  is  invisible,  elastic, 
and  inodorous;  but  the  last  quality  it  seldom  possesses, 
because  it  is  very  seldom  perfectly  dry,  and  when  it  con* 
tains  water  in  solution,  like  alkaline  sulphurets,  its  odour 
is  considerably  fetid.  It  generally  contains  halt  its  weight 
of  water,  and  when  it  is  received  over  water,  its  volume 
is  one-eighth  larger  than  when  received  over  mercury. 

Hydrogen  gas  is  the  lightest  of  all  substances,  except 
light  and  caloric.  When  pure,  it  is  nearly  13  times 
lighter  than  common  air.  It  is  this  extreme  levity 
which  occasions  its  utility  for  inflating  balloons. 

Hydrogen  gas  is  incapable  of  supporting  life,  but  may 
be  inhaled  and  exhaled  a  few  moments  without  fatal 
effects  ;  it  is  returned  by  the  lungs  unaltered,  and  does 
not  therefore  appear  to  be  positively  noxious,  but  only 
operates  by  excluding  oxygen. 

Although  so  currently  called  inflammable  air,  hydrogen 
gas  is  not  capable  of  being  burned,  or  of  supporting 
combustion,  unless  oxygen  be  present. 

That  water  is  in  reality  the  union  of  oxygen  and 
hydrogen,  is  proved  not  only  by  these  gases  being  ob¬ 
tained  by  its  decomposition,  but  bv  reversing  the  experi¬ 
ment  and  producing  water  from  the  gases  themselves. 
Fifteen  parts,  bv  weight,  of  hydrogen,  being  mixed  with 
85  parts  of  oxygen,  and  retained  in  a  close  vessel,  if  the 
hydrogen  be  fired  by  the  electric,  spark,  the  gases  will 
be  converted  into  water,  the  weight  of  which  will  be 
equal  to  both  the  gases  employed,  and  the  gases  disap¬ 
pear. 

The  oil  and  resin  of  vegetables  are  derived  from  the 
decomposition  of  water;  and  composts  are  partly  bene¬ 
ficial  as  manures,  from  the  hydrogen  furnished  in  the 
process  of  putrefaction  :  if  the  compost  be  kept  till  this 
putrefaction  is  nearly  over,  its  value  is  materially  lessened 
as  the  hydrogen  flies  off. 

Hydrogen  combines  with  a  larger  quantity  of  oxygen 
ihan  anv  other  body  ;  its  combustion,  therefore  when 


HYDROGEN. 


6& 


mixed  with  oxygen,  produces  a  more  intense  heat  than 
any  other  combustion.  This  may  be  shown  with  a  blad¬ 
der  tilled  with  oxygen,  and  another  with  hydrogen,  by 
causing  a  stream  from  each  bladder  to  pass  through  a 
tube  upon  a  piece  of  ignited  charcoal,  or  any  other 
burning  combustible.  Each  of  the  bladders  should  be 
furnished  with  a  stop-cock,  and  as  there  is  some  risk  of 
a  violent  explosion,  bladders  may  be  used  with  more 
propriety  than  any  other  vessels. 

Hydrogen  is  capable  of  combining  with  sulphur,  phos¬ 
phorus,  carbon,  and  arsenic;  and  these  compounds  are 
respectively  distinguished  by  the  terms  sulphuretted  hy¬ 
drogen,  phosphuretted  hydrogen,  carburetted  hydrogen, 
and  arseniated  hydrogen.  The  flame  which  it  yields  in 
combustion  is  differently  tinged,  according  to  the  sub¬ 
stance  combined  with  it.  Fireworks  have  been  con¬ 
structed,  in  which  the  diversity  of  colour  in  the  flame 
was  produced  by  an  attention  to  this  property. 

Pit-coal,  by  distillation,  affords  carburetted  hydrogen, 
which  is  employed  in  what  are  called  the  gas  lights. 
The  coal  thus  distilled  is  not  lost,  but  is  converted  into 
coke,  which  is  as  valuable  as  the  coal  from  which  it  was 
produced. 

Sulphuretted  hydrogen  has  an  offensive  smell,  resem¬ 
bling  rotten  eggs.  It  is  produced  by  dissolving  the  sul- 
phurets  in  acids:  that  disengaged  by  the  sulphuric  acid 
burns  with  a  blue  flame ;  that  produced  by  the  nitric 
acid  burns  with  a  yellowish  white  flame ;  the  lattei  acid 
disengages  the  largest  quantity  of  the  gas. 

Phosphuretted  hydrogen,  which  has  also  a  strong  fetid, 
putrid  smell,  may  be  obtained  by  boiling  in  a  retort  a 
little  phosphorus  with  a  solution  of  potass.  If  this-  gas 
comes  in  contact  with  the  air  as  it  escapes  from  the  re¬ 
tort,  it  takes  fire,  and  a  dense  conical  wreath  of  smoke 
arises  from  it.  It  explodes  if  suddenly  mixed  with  oxy¬ 
gen,  oxymuriatic  acid,  or  nitrous  oxide  gas.  I  he  ignis 
fatuus,  or  jack-with-a-lantern,  is  attributed  to  this  disen¬ 
gagement  of  the  gas  from  the  putrid  effluvia  common 
in  swampy  places  where  that  phenomenon  is  observed. 


70  CHEMISTRY. 

Arseniated  hydrogen  may  be  obtained  by  adding  sub 
nhuric  acid,  diluted  with  twice  its  weight  of  water,  to 
four  parts  of  granulated  zinc  and  one  of  arsenic.  I  wo 
parts  of  this  gas,  with  one  of  oxygen,  will  explode  loud¬ 
ly,  and  the  products  are  water  and  arsenious  acid. 

OF  SULPHUR. 

Sulphur,  or  brimstone,  is  a  well-known  substance,  of 
a  yellow  colour,  brittle,  moderately  hard,  devoid  of  smell, 
but  not  entirely  so  of  taste.  Its  specific  gravity  is  1990. 
It  is  a  non-conductor  of  electricity,  and  therefore  becomes 

electric  by  friction.  . 

Sulphur  is  extremely  disseminated,  and  is  obtained 
abundantly,  both  in  a  state  of  purity,  and  from  its  com¬ 
binations  with  other  substances.  It  flows  from  volcanoes, 
and  is  sublimed  from  the  earth  in  some  parts  of  Italy. 
It  is  combined  more  or  less  frequently  with  most  ores, 
and  is  procured  in  large  quantities  from  some  of  them, 
particularly  those  of  iron  and  copper.  In  the  Isle  of 
Anglesea,  it  is  sublimed  from  the  copper  ore,  and  collect¬ 
ed  °in  large  chambers,  which  are  connected  with  the 
kilns  by  means  of  horizontal  flues. 

Sulphur  unites  with  most  of  the  metals,  rendering  them 
brittle,  and  increasing  their  fusibility.  It  is  soluble  in 
oils,  and  by  heat  in  alcohol,  but  water  has  no  immediate 
action  upon  it.  Hydrogen  gas  dissolves  it,  and  is  then 
called  sulphuretted  hydrogen.  This  gas  is  evolved  dur¬ 
ing  the  putrefaction  of  animal  substances.  Sulphur 
unites  with  phosphorus  by  heat ;  but  with  charcoal  it 
does  not  combine. 

If  a  bar  of  iron  or  steel,  at  a  white  heat,  be  rubbed 
with  a  roll  of  sulphur,  the  two  bodies  combine  and  drop 
down  together  in  a  fluid  state,  forming  sulphuret  of  iron, 
a  compound  of  the  same  kind  as  the  native  sulphuret  of 
iron  called  pyrites,  and  which,  from  its  abundance,  sup¬ 
plies  much  sulphur. 

If  potass  or  soda  be  melted  by  a  moderate  heat*  with 
equal  parts  of  sulphur,  in  a  covered  crucible,  it  forms  a 


CARBON. 


71 


substance,  which,  after  cooling,  is  of  a  liver-brown  col¬ 
our.  These  compounds  are  respectively  called  the 
sulphuret  of  potass  or  soda. 

Orpiment,  or  king’s  yellow,  is  a  sulphuret ;  it  is  com¬ 
posed  of  arsenic  and  sulphur  Vermilion  is  the  red 
sulphuret  of  mercury. 

Sulphur  sublimes  at  the  heat  of  170°,  and  is  collected 
in  the  form  of  what  is  called  flowers  of  sulphur:  It 
heated  to  185°,  it  becomes  very  fluid,  but  by  n  continu¬ 
ance  of  the  heat  its  fluidity  diminishes,  and  it  even  be¬ 
comes  thick  ;  on  being  allowed  to  cool,  its  former  fluidity 
returns  before  it  becomes  solid.  If  as  soon  as  the 
sulphur  has  begun  to  congeal,  the  inner  liquid  part  be 
poured  out,  the  internal  cavity  will  exhibit  long  needle- 
shaped  crystals  of  an  octahedral  figure. 

Sulphur  combines  with  oxygen  in  four  definite  propor¬ 
tions,  forming  an  interesting  class  of  acids,  viz .  the 
sulphurous,  hypo-sulphurous,  sulphuric,  and  hypo- 
sulphuric.  From  these  combinations  it  is  inferred  that 
its  prime  equivalent  is  2,  and  the  density  of  its  vapour  is 
1.111,  equal  to  that  of  oxygen. 

Sulphur  is  applied  to  many  important  uses.  It  is  em¬ 
ployed  in  medicine,  it  enters  into  the  composition  of 
sulphuric  acid,  of  gunpowder,  and  of  the  common  com¬ 
position  for  paying  the  bottom  ol  ships.  Its  (urnes  are 
employed  in  bleaching  silk  and  wool,  and  checking  the 
progress  of  vinous  fermentation.  Common  matches,  for 
lighting  fires,  are  tipped  with  sulphur. 

OF  CARBON. 

Vegetables;  when  burnt  or  distilled  in  close  vessels, 
till  their  volatile*  parts  are  entirely  separated,  leave  a 
black,  brittle,  and  cinerous  residuum,  which  constitutes 
the  greater  part  of  the  woody  fibre,  and  is  called  char¬ 
coal.  Charcoal  contains  a  portion  of  earthy  and  saline 
matters,  but  when  entirely  freed  from  these  and  other 
impurities,  a  solid,  simple,  combustible  substance  remains, 
which  is  called  carbon. 


CHEMISTRY. 


72 

Carbon  exists  naturally  in  a  state  of  greater  purity 
than  it  can  be  prepared  by  art.  The  diamond  is  pure 
carbon  crystallized.  The  diamond,  when  pure,  is  colour¬ 
less  and  transparent.  It  is  the  hardest  substance  known 
and,  as  it  sustains  a  considerable  degree  of  heat  un¬ 
changed,  it  was  formerly  supposed  to  be  incombustible. 
It  may,  however,  be  consumed  by  a  burning-glass,  and 
even  by  the  heat  of  a  furnace.  The  difficulty  of  burn¬ 
ing  it  appears  to  arise  from  its  hardness;  for  Morveau  and 
Tennant  have  rendered  common  charcoal  so  hard  by  ex¬ 
posing  it  for  some  time  to  a  violent  fire  in  close  vessels, 
that  it  endured  a  red  heat  without  catching  fire.  Com¬ 
mon  charcoal  contains  only  04  parts  of  diamond,  or  pure 
carbon,  and'36  of  oxygen  in  every  100. 

The  common  charcoal  of  commerce  is  usually  pre¬ 
pared  from  young  wood,  which  is  piled  up  near  the 
place  where  it  is  cut,  in  conical  heaps,  covered  with 
earth,  and  burnt  with  the  least  possible  access  of  air. 
When  the  fire  is  supposed  to  have  penetrated  to  the  cen¬ 
tre  of  the  thickest  pieces,  it  is  extinguished  by  entirely 
closing  the  vents.  When  charcoal  is  wanted  very  pure, 
the  product  of  this  mode  of  preparing  it  will  not  suffice ; 
for  the  manufacturing  of  the  best  gunpowder,  it  is  dis¬ 
tilled  in  iron  cylinders.  Chemists  prepare  it  in  small 
quantities,  in  a  crucible  covered  with  sand  ;  and,  after 
they  have  thus  prepared  it  they  pound  it,  and  wash  away 
the  salts  it  contains  hy  muriatic  acid  ;  the  acid  is  removed 
by  the  plentiful  use  of  water,  and  afterwards,  the  char¬ 
coal  is  exposed  to  a  low  red  heat.  Pure  charcoal  is  per¬ 
fectly  tasteless,  and  insoluble  in  water. 

Charcoal,  newly  prepared,  absorbs  moisture  with 
avidity.  It  also  absorbs  oxygen,  and  other  gases  which 
are  condensed  in  its  pores,  in  quantity  many  times  ex 
ceeding  its  own  bulk,  and  are  given  out  unaltered 
Fresh  charcoal,  allowed  to  cool  without  exposure  to  air, 
and  the  gas  then  admitted,  will  absorb  2.25  times  its 
balk  of  atmospheric  air  immediately,  and  .75  more  in 
four  or  five  hours;  of  oxygen  gas,  about  1.8  immediately, 
and  slowly,  1  more;  of  nitrogen  gas,  1.65  immediately; 


/ 


CARBON.  10 

of  nitric  oxide,  8.5  very  slowly ;  of  hydrogen  gas,  about 
1.9  immediately;  carbonic  acid  gas,  14.3  immediately. 
The  greater  part  of  these  gases  are  expelled  by  a  heat 
below  212°,  and  a  portion  even  by  immersing  the  char¬ 
coal  in  water.  These  absorptions  are  piomoted  by  a 
low  temperature  ;  but,  at  an  elevated  temperature,  chai- 
coal  has  such  an  affinity  for  oxygen,  that  it  will  abstract 
it  from  almost  all  its  combinations.  Hence,  its  utility  in 
reviving  metals. 

Fossil  coal,  and  all  kinds  of  bitumen,  contain  a  large 
quantity  of  carbon :  it  is  also  contained  in  oils,  resins, 

sugar,  and  animal  substances. 

Charcoal  is  one  of  the  most  unchangeable  substances ; 
if  the  access  of  air  be  prevented,  the  most  intense  heats 
have  no  other  effect  than  that  just  mentioned  of  harden¬ 
ing  it,  and  rendering  its  colour  a  deeper  black.  Insolu- 
able  in  water,  and  incapable  ot  putrefaction,  it  under¬ 
goes  no  change  by  mere  exposure  or  age  ;  and  stakes, 
and  other  materials  of  wood  which  have  been  charred, 
or  superficially  converted  into  charcoal,  have  been  pie- 
served  from  decay  for  thousands  of  years;  the  ancients 
availed  themselves  of  this  mode  of  preparing  stakes  which 
were  to  be  driven  into  the  ground  for  foundations  and 
other  purposes. 

The  combinations  of  carbon  with  various  substances, 
are  called  carburets.  Steel  is  a  combination  of  iron  and 
carbon,  in  which  the  proportion  of  carbon  is  very  small, 
only  about  a  two  hundredth  part;  it  is  to  its  carbon  that 
it  owes  its  valuable  property  of  admitting  to  be  temper¬ 
ed.  Cast-iron  contains  more  carbon  than  steel,  but  this 
difference  is  not  the  only  cause  of  the  difference  of  the 
properties  of  iron  in  the  two  states;  from  its  cat  bon, 
however,  cast-iron  admits  of  being  made  hard  or  soft, 
nearly  in  the  same  manner  as  steel.  Plumbago  contains 
90  parts  of  carbon,  and  but  ten  of  iron;  it  is  from  this 
excess  of  carbon,  called  a  hyper-carburet  of  iron.  I  he 
name  of  black  lead,  by  which  it  is  most  generally  known, 
is  evidentlv  improper,  as  it  contains  not  a  paiticc  o 
lead.  On  the  contrary,  the  connexion  of  plumbago  with 
7 


74 


CHEMISTRY. 


iron  might  be  inferred  from  its  resemblance  in  soma 
respects"  to  that  kind  of  cast-iron  which  contains  most 
carbon;  their  fracture  is  much  alike;  and  very  line 
filings  of  the  iron  tinge  the  hands  nearly  in  the  same 
manner  as  the  powdered  plumbago.  Yet  cast-iron  sel¬ 
dom  contains  more  than  a  forty-fifth  part  of  its  weight 

of  carbon.  ♦ 

Charcoal  possesses  the  singular  property  of  combining 
with,  and  destroying  the  odour,  colour,  and  taste,  of  va¬ 
rious  substances.  Putrid  and  stinking  water  may  be 
rendered  sweet  by  filtering  it  through  charcoal-powdoi. 
or  even  by  agitation  with  it.  Common  vinegar  boiled 
with  charcoal-powder,  becomes  perfectly  limpid.  Saline 
solutions  that  are  tinged  yellow  or  brown,  are  rendered 
colourless  in  the  same  way,  so  that  they  will  afford  white 
crystals.  Malt  spirit  may  be  freed  from  its  disagreeable 
flavour  by  distillation  with  about  — oo"  °f  bs  weight  of 
charcoal.  Tainted  vessels,  after  having  been  well  scoured, 
may  have  every  remaining  taint  removed  by  rinsing 
them  with  charcoal-powder ;  and  this  powder  will  also 
restore  the  sweetness  of  flesh-meat  but  slightly  tainted 
with  putridity.  As  a  dentrifice,  charcoal  in  the  state  of 
an  impalpable  powder,  is  unrivalled,  at  once  whitening 
the  sound  teeth,  and  sweetening  the  breath  by  neutrali¬ 
zing  the  fetor  that  arises  from  those  which  are  carious, 
or  from  a  scorbutic  state  of  the  gums. 

When  charcoal  is  burnt  in  oxygen  gas,  nearly  the 
whole  of  it  disappears:  it  is  converted  by  its  combina¬ 
tions  with  oxvgen  into  an  aeriform  fluid,  which,  having 
the  properties  of  an  acid,  is  called  carbonic  acid  §as> 
It  contains  28  parts,  by  weight,  of  charcoal,  and  72  of 
oxvgen  in  every  100.  It  was  discovered  by  I)r.  Black, 
in  1755,  and  the  discovery  constitutes  a  memorable 
epoch  in  the  history  of  chemistry,  as  it  was  attended 
with  so  clear  a  demonstration  of  the  fact,  that  gaseous 
substances  could  become  concrete,  or  form  a  part  of  solid 
substances,  and  that,  on  the  contrary,  solid  substances 
could  assume  the  gaseous  form. 

Carbonic  acid  gas  is  nearly  twice  as  heavy  as  atmi 


CARBON. 


75 


spheric  air,  and  it  may  therefore  be  poured  from  one  ves¬ 
sel  to  another,  or  retained  in  a  cask  and  drawn  oif  like 
other  liquors.  Though  invisible,  yet  if  contained  in  a 
glass,  the  presence  of  something  different  from  common 
air  may  be  discovered  by  lighting  a  piece  of  paper,  and 
putting  it  into  a  glass  ;  the  light  will  instantly  go  out, 
and  the  smoke  becoming  entangled  in  this  heavy  gas, 
will  show  the  quantity  of  the  gas  that  may  be  present 
The  extinction  of  fire  by  this  gas  is  instant  and  com¬ 
plete;  and  when  by  any  accident  it  is  breathed,  it  pre¬ 
vents  the  power  of  speech,  and  rapidly  destroys  life. 
As  it  is  evolved  in  the  process  of  fermentation,  it  is  often 
present  in  vats,  and  the  public  journals  frequently  record 
instances  of  persons  who  have  incautiously  descended 
into  these  vessels  to  clean  them,  perishing  from  its  bane 
ful  effects  in  a  few  moments. 

Carbonic  acid  gas  is  always  the  result  of  the  combus 
tion  of  charcoal,  which  cannot  be  burnt  in  a  close  apart 
ment,  without  imminent  hazard  of  suffocation  to  the 
persons  present.  This  gas  is  often  contained  in  deep  old 
wells,  and  places  which  have  been  long  closed  ;  wherever 
it  is  suspected  to  exist,  it  will  be  proper  to  introduce  a 
lighted  candle,  and  if  that  burns  as  usual,  no  danger  need 
be  apprehended  ;  but  if  it  be  extinguished,  it  may  be 
taken  for  granted  that  the  air  is  unlit  to  breathe.  A 
quantity  of  water,  particularly  if  mixed  with  quick-lime, 
will,  if  thrown  into  a  suspected  place,  absorb  the  car¬ 
bonic  acid  which  may  be  present.  Carbonic  acid  gas 
constitutes  what  miners  call  choke-damp. 

Carbonic  acid,  though  so  deleterious  when  breathed, 
often  forms  a  palatable  wholesome  ingredient  in  food,  as 
it  possesses  the  strongly  antiseptic  properties  of  carbon,  its 
base.  Hence  the  acid  taste  of  Pyrrnont,  Spa,  and  other 
mineral  waters  ;  hence  the  sparkling  and  agreeable  brisk¬ 
ness  of  fermented  liquors,  such  as  beer,  cider,  &c.  Yeast, 
from  the  large  quantity  it  contains  of  it,  has  performed 
wonderful  cures  in  putrid  diseases.  The  atmosphere 
contains  a  very  small  quantity  of  this  gas,  the  use  of 
which  may  be  to  neutralize  the  putrid  miasmata  con* 


7G 


C11BMIST11Y. 


tinually  flying  about.  Water  may  by  pressure  be  cau» 
ed  to  combine  with  nearly  three  times  its  own  bulk  of 

carbonic  acid  gas.  . .  .'  .  .  n 

The  combinations  of  carbonic  acid  with  other  substan¬ 
ces  are  called  carbonates.  Common  chalk,  lime-stone, 
and  marbles,  are  all  carbonates,  and  in  their  chemical 
composition  differ  hut  little  from  each  other.  Carbonic 
acid  gas  may  be  obtained  lrom  any  of  these,  by  putting 
them  into  a” retort  in  powder,  and  pouring  upon  them  a 
diluted  acid,  for  example  the  sulphuric.  1  he  gas  must 
be  collected  by  the  pneumatic  apparatus.  A  cubical 
inch  of  marble  contains  as  much  carbonic  acid,  as,  in  tne 
state  of  gas,  would  fill  a  vessel  of  six  gallons. 

OF  PHOSPHORUS. 

Phosphorus  is  a  yellowish,  transparent  substance,  of 
the  consistence  of  wax.  it  is  luminous  in  the  dark  at 
common  temperatures,  and  at  07“  it  emits  a  white 
smoke.  It  is  rapidly  consumed  at  122  .  It  is  preserved 
by  keeping  it  in  water:  the  water  has,  however,  the 
effect  of  rendering  it  opaque;  and  even  exposure  to  light 

alters  it  in  some  degree.  . 

Phosphorus  was  originally  prepared  from  urine,  by  a 
tedious  and  disagreeable  process  ;  but  Gahn,  a  bvvedish 
chemist,  having  discovered  that  it  existed  in  bones,  it  is 
now  prepared  from  this  class  of  bodies.  1  he  bones  are 
calcined  till  they  cease  to  smoke,  after  which  they  are 
reduced  to  a  fine  powder.  This  powder  is  put  into  a 
glass  vessel,  and  sulphuric  acid  is  gradually  poured  upon 
it  till  the  further  addition  of  acid  occasions  no  extrica¬ 
tion  of  air  bubbles.  This  mixture  is  largely  diluted 
with  water,  well  agitated,  and  kept  hot  for  some  hours  ; 
it  is  then  filtered,  and  afterwards  evaporated  slowly,  till 
a  quantity  of  white  powder  lulls  to  the  bottom,  ibis 
powder,  by  a  second  iiltcrution,  is  separated,  and  thrown 
away.  The  evaporation  is  the#  resumed ;  and  when¬ 
ever  any  white  powder  appears,  the  liberation  must  be 
repeated,  in  order  to  separate  it.  During  the  whole  pro- 


PHOSPHORUS. 


77 


ccss,  what  remains  on  the  filter  must  he  washed  yyith 
pure  water,  and  this  water  added  to  the  liquor.  The 
evaporation  is  continued  till  all  the  moisture  disappears, 
and  nothing  but  a  dry  mass  remains.  This  mass  is  put 
into  a  crucible,  and  kept  melted  in  the  fire,  til!  it  ceases 
to  yield  a  sulphurous  smell;  it  is  then  poured  out. 
When  cold,  it  resembles  a  brittle  glass:  it  is  pounded  in 
a  glass  mortar,  and  mixed  with  one-third,  by  weight,  oi 
charcoal  dust.  This  mixture  is  put  into  an  earthenware 
retort,  to  which  is  adapted  a  receiver,  containing  a  little 
water.  In  a  short  time  after  the  retort  and  its  contents 
have  become  red-hot,  the  phosphorus  passes  into  the  re¬ 
ceiver,  drop  by  drop.  It  is  generally  formed  into  small 
cylinders,  by  moulding  it  under  lukewarm  water,  in 
glass  tubes,  or  by  putting  a  cork  into  the  extremity  of  the 
pipe  of  a  glass  funnel,  into  which  hot  water  may  then  be 
poured,  and  the  phosphorus  being  dropt  in,  will  mould 
itself.  From  the  remark  made  above,  respecting  the 
low  temperature  at  which  it  burns,  it  is  necessary  to 
take  great  care  that  none  of  it  adheres  to  the  hand, 
especially  under  the  nails,  whence  it  would  be  with 
difficulty  extracted  ;  as  the  heat  of  the  body  would  kin¬ 
dle  it,  and  it  burns  with  extreme  ardour.  If,  however, 
it  be  thoroughly  mixed  with  several  times  its  bulk  of 
hog’s  lard,  it  may  be  held  in  the  hand  wdthout  injury. 

Phosphorus  possesses  a  prodigious  divisibility.  A  quar¬ 
ter  of  a  grain  being  administered  in  some  pills  to  a  per¬ 
son  who  w'as  afterwards  opened,  all  the  internal  parts 
were  found  to  be  luminous,  and  even  the  hands  of  the 


person  who  opened  the  body  had  the  same  appearance. 

Phosphorus  combines  with  oxygen,  hydrogen,  nitrogen, 
sulphur,  most  of  the  metals,  and  some  of  the  earths.  By 
combining  with  oxygen,  that  is,  after  combustion,  it 
forms  phosphoric  acid.  When  the  phosphoric  acid  is 
combined  with  any  substance,  that  substance  is  called  a 
phosphate.  The  phosphorus  in  bones  is  in  a  state  of 
phosphate  of  lime.  The  combination  of  phosphorus  with 
iron  forms  that  kind  of  iron  called  cold-short,  which  is 
brittle  when  cold,  though  malleable  when  heated. 


7  * 


CHEMISTRY. 


78 

Phosphorus,  rubbed  in  a  mortar  with  iron  filings,  takes 
fire  immediately.  Phosphoric  match-bottles  .are  pre¬ 
pared  bv  mixing  one  part  of  flour  of  sulphur  with  eight 
of  phosphorus.  If  a  very  small  quantity  of  this  mixture 
he  taken  out  on  the  point  of  a  match,  and  rubbed  upon 
a  cork,  or  any  similar  body,  the  match  becomes  lighted. 

At  the  temperature  of  70°  F.,  phosphorus  combines 
with  oil,  and  forms  a  compound,  which,  in  contact  with 
atmospheric  air,  becomes  luminous  in  the  dark. 

Put  one  part  of  phosphorus  into  six  parts  of  good  olive 
oil,  or  oil  of  cinnamon,  which  is  preferable.  Digest  it  in 
a  gentle  sand  heat,  until  the  phosphorus  is  dissolved,  on 
which,  immediately  cork  the  bottle.  If  this  oil  be  rubbed 
on  any  thing,  it  immediately  becomes  luminous  in  the 
dark,  and  yet  has  not  sufficient  heat  to  burn  the  sub¬ 
stance. 

OF  WATER. 


The  composition  of  water  has  already  been  inciden¬ 
tals  mentioned ;  it  consists  of  85  parts  of  oxygen,  and 
15  of  hydrogen.  It  is  a  product  of  combustion,  being 
formed  whenever  hydrogen  is  united  to  oxygen  ;  for  these 
two  bodies  are  not  known  to  be  capable  of  uniting  in  any 
proportion  but  that  which  forms  water.  The  proofs  of 
the  composition  of  water  are  complete;  this  fluid  may 
be  decomposed,  that  is,  separated  into  the  gases  of  which 
it  is  composed  ;  or  the  gases  may  be  converted  into  watei. 

Water  is  capable  of  existing  in  four  different  states, 
1.  that  of  ice ;  2.  that  of  water,  or  the  liquid  state ;  3.  that 
of  steam,  or  the  gaseous  state ;  4.  in  combination  with 
crystals  or  other  solids. 

1.  Ice  is  the  simplest  state  of  water;  if  entirely  de 
prived  of  caloric,  it  would  still  be  ice,  only  increasing  in 
hardness  as  the  caloric  was  abstracted.  It  is  elastic,  and 
when  long  kept  much  below  the  point  at  which  it  is 
formed,  it  becomes  extremely  hard.  \v  hen  pulverized, 
it  is  white.  As  one  of  the  amusements  of  the  court  of 
Russia,  in  the  severe  winter  of  1740,  a  palace  was  con¬ 
structed  cntirelv  of  ice  hewn  from  the  river  .Neva ;  and 


WATI'.R. 


79 


it  cannon  made  of  the  same  material,  drove  a  hempen 
bullet  through  a.  board  two  inches  thick  at  the  distance 
of  sixlv  paces.  Water  expands  in  passing  to  the  state 
of  ice,  with  a  force  that  produces  most  astonishing 
effects;  rending  trees,  and  separating  immense  iragments, 
from  the  rocks  and  mountains.  This  expansion  is  owing 
to  the  new  arrangement  of  its  particles;  the  needles  ot 
the  crystals  crossing  each  other,  either  at  angles  of  GO 
or  120°.  Ice  is  converted  into  water  when  its  tempera 
'  ture  is  raised  above  32°. 

2.  Water  retains  its  character  as  a  fluid,  at  all  tem¬ 
peratures  between  32°  and  212°.  it  is  employed  as  the 
standard  of  comparison  in  all  tables  of  specific  gravities. 

Water,  when  perfectly  pure,  possesses,  a  high  degree 
of  transparency,  and  is  entirely  destitute  of  colour,  taste, 
and  smell.  It  is  nearly  inelastic,  and  consequently  incom¬ 
pressible.  It  can  only  he  obtained  pure  by  distillation; 
for  as  it  is  capable  of  holding  a  greater  number  o(  sub¬ 
stances  in  solution  than  any  other  fluid,  the  facility  with 
which  it  becomes  impregnated  with  foreign  substances 
must  be  obvious. 

3.  When  water  is  converted  into  vapour,  it  combines 
with  above  five  times  the  quantity  of  caloric  which  would 
be  required  to  bring  ice-cold  water  to  the  boiling  heat; 
it  is  estimated  to  till  a  space  1800  times  greater  than  in 
the  state  of  water;  and  the  large  quantity  ot  caloric 
with  which  it  is  combined,  is  the  only  cause  ot  the  differ¬ 
ence.  This  refers  to  water  under  the  common  pressure 
of  the  atmosphere.  When  this  pressure  is  lessened,  as 
under  an  exhausted  receiver,  water  assumes  the  state  of 
vapour  at  a  very  gentle  heat ;  and  when  retained  in  a 
sufficiently  strong  vessel,  as  in  Papin’s  digester,  it  may  be 
rendered  red-hot  without  being  converted  into  steam. 
The  elasticity  of  steam  is  prodigious ;  and  it  increases 
with  the  heat  at  which  the  steam  is  formed.  It  has  been 
found  bv  experiments,  that  the  expansive  force  of  steam 
exceeds  that  of  gunpowder. 

4.  The  singular  tenacity  with  which  water  is  held 
by  a  great  number  of  substances,  is  an  interesting  fact. 


80 


CHEMISTRY 


Saussurc  has  proved  (hat  alumme  will  retain  one-tenth 
of  its  weight  of  water,  at  a  heat  which  will  keep  iron  in 
fusion;  lime  retains  water  with  nearly  the  same  force, 
and  calcined  plaster  of  Paris  is  changed  from  a  state  o, 
powder  to  that  of  a  solid,  by  combining  with  a  large 
portion  of  water;  some  salts,  though  tolerably  hard  and 
dry,  are  combined  with  as  much  water,  as  at  a  boiling 
heat  would  hold  them  in  solution ;  crystals  owe  their 
transparency,  and  even  their  solidity,  to  the  water  com¬ 
bined  with  them,  for  they  lose  both  these  properties  as 
soon  as  the  water  is  abstracted.  By  entering  into  many 
of  these  combinations,  it  is  evident  that  water  is  deprivec 
of  a  greater  quantity  of  caloric  than  in  a  state  ol  ice, 
and  it  is  to  this  cause  that  we  must  attribute  its  hardness 


in  gems. 


MINERAL  WATERS. 


The  purest  water  which  nature  affords  is  melted 
snow,  or  of  rain  newly  fallen,  and  collected  in  open 
fields,  at  a  distance  from  houses,  or  contaminated  atmo¬ 
sphere.  The  water  of  rivers  and  lakes  is  next  in  pun:y, 
especially  where  it  is  a  rocky  or  gravelly  bed.  Stag¬ 
nant  water,  and  that  of  marshes,  is  in  general  exceed¬ 
ingly  impure,  and  often  offensive  to  the  taste,  as  lt^is 
largely  impregnated  with  principles  derived  from  tne 
putrefaction  of  animal  and  vegetable  matters.  All  these 
waters,  however,  possess  the  property  called  softness ; 
that  is,  they  will  dissolve  soap.  Spring  waters  are  gene¬ 
rally  hard:  they  will  not  dissolve  soap;  and  are,  there¬ 
fore,  unfit  for  anv  domestic  purposes,  and  tor  manufac¬ 
turers.  This  arises  from  their  containing  earths  and 
minerals  in  solution.  Springs  which  supply  water  o  a 
more  agreeable  taste  than  rain,  river,  or  lake  water, 
are  the  most  abundant;  and  they  always  contain  car¬ 
bonic  acid.  Other  impregnations  impair  their  taste; 
and,  when  they  are  in  such  access  as  to  give  a  marked 
character  to  the  water,  the  waters  of  such  springs  are 

called  Mineral  waters .  •  . ,  . 

It  may  often  be  important  to  obtain  a  general  idea  of 


MINERAL  WATERS. 


81 


the  impregnations  of  a  particular  spring,  in  order  to  know 
whether  it  can  be  safely  taken  with  food,  or  is  likely  tc 
be  useful  as  a  medicine,  or  ought  to  be  wholly  rejected. 
We  shall  therefore  give  a  short  account  of  the  tests,  by 
which  the  most  usual  impregnations  may  be  detected. 

The  sensible  qualities  of  water,  such  as  transparency, 
colour,  taste,  and  smell,  should  be  examined,  if  possible, 
at  the  instant  it  comes  from  the  spring.  If  the  water 
must  necessarily  be  examined  at  a  distance,  a  bottle, 
with  an  air-tight  stopper,  should,  at  the  fountain-head, 
be  completely  tilled  with  it,  in  order  to  leave  no  space 
for  air.  The  specific  gravity  should  also  be  taken.  To 
note  exactly  the  sensible  qualities  of  the  water,  will 
often  indicate  the  re-agents  which  may  be  employed  to 
denote  its  composition. 

Spring  water  generally  contains  more  or  less  carbonic 
acid,  which  imparts  an  agreeable  sparkling  and  brisk¬ 
ness ;  like  that  exhibited  by  fermented  liquors.  Where 
no  colouring  matter  is  present,  the  sparkling  induces 
us  to  suppose  this  water  more  transparent  than  other 
waters. 


Carbonic  acid  sinks  the  taste  of  every  other  ingredient 
in  waters ;  and,  therefore,  such  waters  should  not  only 
be  tasted  at  the  spring,  but  some  time  after  they  have 
been  exposed  to  the  air,  or  after  they  have  been  boiled 
as  the  carbonic  acid  will  then  have  escaped.  The  tinc¬ 
ture  of  litmus  will  discover  whether  an  acid  is  presen 
in  water,  and  as  the  carbonic  is  the  only  acid  which 
separated  by  exposure  to  the  air,  this  exposure,  if  i 
deprive  the  water  of  the  power  of  reddening  litmus- 
paper  or  its  solution,  will  show  whether  the  acid  is 
the  carbonic  or  not. 

Water  containing  carbonic  acid  will  hold  a  consider¬ 
able  quantity  of  carbonate  of  lime  in  solution.  Lime  is 
detected  most  effectually  by  oxalic  acid,  which  separates 
it  from  all  its  combinations,  and  forms  with  it  an  insolu¬ 
ble  precipitate,  unless  an  excess  of  acid  be  present,  for 
then  the  precipitate  will  be  re-dissolved.  It  is,  therefore 
best  to  use  the  oxalate  of  ammonia  or  potass,  in  order 

that  the  alkali  may  neutralize  the  acid  in  solution. 

F 


g2  CHEMISTRY. 

Diluted  muriate  of  barytes  will  form  a  precipitate 
with  water  containing  sulphuric  .acid.  T  e  precipi  a  e 
is  white,  and  insoluble  in  diluted  muriatic  acid. .  . 

The  nitrate  of  silver  occasions  a  white  precipitate  or 
cloud  in  water  containing  muriatic  acid. 

Alkalies  held  in  solution,  or  alkaline  or  earthy  carbo 
nates,  change  paper  stained  with  turmeric  to  a  brown, 
or  reddish  brown,  and  light  vegetable  reds  are  rendered 
blue.  The  volatile  alkali  may  be  distinguished  by  its 
smell.  Earthy  and  metallic  carbonates  are  precipitated 

by  boiling.  ,  , 

Iron  is  very  common  in  mineral  waters ;  it  may  be 
detected  by  its  forming  a  purple  or  blackish  precipitate 
with  tincture  of  galls,  or  blue  with  prussiate  ot  potass. 

Pure  ammonia,  or  lime-water,  precipitates  magnesia 
and  alumine,  and  no  other  earths,  provided  the  carbonic 
acid  has  previously  been  separated  by  a  fixed  a;. tali  and 

Doiling.  ,  .  .  . 

The  mineral  acids,  when  uncombined,  give  a  ,'erma- 
nent  red  to  litmus  paper,  both  before  and  after  the  water 
has  been  boiled  ;  whereas,  the  redness  communicated  by 
the  carbonic  acid  gas  goes  oil  as  the  paper  dries. 

Waters  containing  the  sulphate  of  copper,  may  be  de¬ 
tected  bv  their  giving  the  colour  of  copper  to  a  polished 
plate  of  iron  immersed  in  them. 

Sulphate  of  iron  is  precipitated  by  alcohol. 

The  specific  gravity  of  sea-water  is  generally  l.O'ibJ. 
It  holds  about  Vo  of  its  weight  of  muriate  of  soda  in  so¬ 
lution,  with  a  small  quantity  of  muriate  of  magnesia,  and 
a  still  smaller  proportion  of  the  sulphate  of  hme.  At  a 
distance  from  land,  it  is  colourless  and  void  of  smell,  but 
intensely  saline  and  bitter. 

In  analyzing  waters  with  exactness,  the  gaseous  pirn 
ducts  they  a  fiord  are  carefully  collected  and  examined. 

OF  THE  AIR. 

The  atmosphere  may  be  said  in  general  terms  to  con¬ 
sist  of  oxygen  and  nitrogen?  but  atmospheric  air,  even 


THE  AIR. 


83 


when  purest,  always  contains  a  small  proportion  of  other 
principles.  Murray  states  its  exact  composition  as  follows 

By  measure.  By  weight. 

Nitrogen  gas  -  -  •  •  -  -  -  77.5  75.55 

Oxygen  gas .  21.0  23.32 

Aqueous  vapour . -  1.42  1.03 

Carbonic  acid  gas .  *08  .10 

100.0  100.0 

As  considerable  quantities  of  hydrogen  escape  from 
the  earth,  it  might  be  presumed  that  it  would  be  found 
in  the  atmospheric  air,  but  as  the  atmospheric  air  has 
no  chemical  attraction  for  it  in  any  proportion  that  can  be 
detected,  it  peobably  escapes,  by  its  levity,  beyond  the 
heights  to  which  we  have  access.  Dalton’s  experiments 
evince  that  the  proportion  of  carbonic  acid  gas  does  not 
exceed  a  thousandth  part,  though  a  higher  estimate  is 
generally  made. 

Atmospheric  air  is  destitute  of  taste  and  smell,  highly 
compressible,  and  perfectly  elastic.  It  supports  animal 
life,  directly  bv  the  oxygen  it  affords  to  the  lungs,  where 
the  blood  combines  chemically  with  it;  and  indirectly, 
by  its  mechanical  properties  in  equalizing  the  tempera¬ 
ture  of  the  globe,  and  preventing  too  rapid  an  evaporation 
of  the  moisture  of  the  body.  It  is  also  not  less  necessary 
to  vegetable  life,  as  the  vehicle  for  the  distribution  of 
water,  and  in  its  decompositions,  by  furnishing  them  with 
nitrogen,  carbonic  acid,  and  other  principles. 

Atmospheric  air  contains  the  only  proportion  of  oxy¬ 
gen  which  is  subservient  to  the  purposes  of  existence  ; 
all  the  known  gases  have  been  tried.  None  of  them  ex¬ 
cept  the  nitric  oxide,  ^ean  be  breathed  for  even  a  few 
moments;  and  even  the  nitric  oxide,  during  the  short 
time  which  it  remains  on  the  lungs,  produces  a  suspen¬ 
sion  of  the  proper  functions  of  the  mind.  In  all  the 
gases,  also,  combustion  is  either  intemperate  or  wholly 
stopped.  Notwithstanding  the  multiplied  compositions 
and  decompositions  which  are  continually  going  on  at 


CHEMISTRY. 


84 

the  surface  of  the  earth,  the  due  proportion  of  oxygen 
in  the  air  is  still  maintained  with  a  precision  truly 

astonishing. 

The  specific  gravity  of  the  air  is  less,  the  greater  the 
proportion  of  aqueous  moisture  which  it  contains.  .  Hence, 
aeronauts  find  that  their  balloon  sinks  when  passing  over 
the  sea,  where  the  air  is  moister  than  over  the  land. 


OF  GAS. 

This  term  is  applied  to  all  permanently  elastic  fluids, 
simple  or  compound,  except  the  atmosphere,  to  which 

the  term  air  is  appropriated. 

Some  of  the  gases  exist  in  nature  without  the  aid  ot 
art,  and  may,  therefore,  be  collected  ;  others,  on  the  con¬ 
trary,  are  only  producible  by  artificial  means. 

All  gases  are  combinations  of  certain  substances,  re¬ 
duced  to  the  gaseous  form  by  the  addition  of  caloric.  It 
is,  therefore,  necessary  to  distinguish,  in  every  gas,  the 
matter  of  heat  which  acted  the  part  of  a  solvent,  and 
the  substance  which  forms  the  basis  of  the  gases. 

Gases  are  not  -contained  in  those  substances  from 
which  we  obtain  them  in  a  state  ot  gas,  but  owe  their 
formation  to  the  expansive  property  of  caloric. 

The  formation  of  gases. — The  different  forms  under 
which  bodies  appear,  depend  upon  a  certain  quantity  of 
caloric,  chemically  combined  with  them.  I  he  veiy  foi- 
mation  of  gases  corroborates  this  truth.  The  proouciioi, 
totally  depends  upon  the  combinations  of  the  particulai 
substances  with  caloric;  and  though  called  permanently 
elastic,  they  are  only  so  because  we  cannot  so  far  reduce 
their  temperature,  as  to  dispose  them  to  part  with  it; 
otherwise  they  would  undoubtedly  become  fluid  or  solid. 

Water,  for  instance,  is  a  solid  substance  in  all  degrees 
below  32°  of  Fahrenheit’s  scale ;  above  this  temperature 
it  combines  with  caloric,  and  it  becomes  a  fluid.  It 
retains  its  liquid  state  under  the  ordinary  pressure  of  the 
atmosphere,  till  its  temperature  is  augmented  to  212  . 
It  then  combines  with  a  larger  portion  of  caloric,  and  is 


ALCOHOL. 


85 


converted,  apparently,  into  gas,  or  at  least  into  elastic 
vapour ;  in  which  state  it  would  continue,  if  the  tempe¬ 
rature  of  our  atmosphere  was  above  212°.  Gases  are 
therefore  solid  substances,  between  the  particles  of  which 
a  repulsion  is  established  by  the  quantity  of  caloric. 

But  as  in  the  gaseous  water  or  steam,  the  caloric  is 
retained  but  with  little  force,  on  account  of  its  quitting 
the  water  when  the  vapour  is  merely  exposed  to  a  lower 
temperature,  we  do  not  admit  steam  among  the  class  of 
gases,  or  permanently  elastic  aeriform  fluids.  In  gases, 
caloric  is  united  by  a  very  forcible  affinity,  and  no  dimi¬ 
nution  of  temperature,  or  increase  of  pressure,  that  has 
ever  yet  been  effected,  can  separate  it  from  them.  Thus . 
the  air  of  our  atmosphere,  in  the  most  intense  cold,  or 
when  very  strongly  compressed,  still  remains  in  the  acii- 
form  state;  and  hence  is  derived  the  essential  characters 
of  gases,  namely,  that  they  shall  remain  aeriform,  under 
all  variations  of  pressure  and  temperature. 

OF  ALCOHOL. 

Alcohol,  or  the  purely  spiritous  part  of  liquors  which 
have  undergone  the  vinous  fermentation,  and  no  other, 
is  transparent  and  colourless  like  water  ;  its  taste  is  high¬ 
ly  pungent,  but  agreeable.  It  is  extremely  inflammable, 
and  w'hen  set  on  fire  it  leaves  no  residuum.  Its  specific 
gravity  is  0.800  ;  and  from  its  brightness  and  extreme 
fluidity,  the  bubbles  which  are  formed  on  its  surface, 
break  with  rapidity.  It  is  not  frozen  even  by  the  ex¬ 
treme  cold  of  05° ;  but  it  has  been  frozen  by  the  sudden 
abstraction  of  its  caloric  in  the  vacuum  of  an  air-pump. 
In  a  vacuum,  it  boils  at  56°  ;  in  the  air  it  is  converted  into 
vapour  at  55°,  and  boils  at  105°.  It  is  from  its  being 
converted  into  vapour  much  sooner  than  water,  that  it 
is  easily  separated  by  distillation  from  wine,  beer,  and 
other  liquors  which  contain  it.  All  these  liquors  owe 
their  strength  to  the  quantity  of  alcohol  they  contain  : 
the  best  port-wine  contains  about  one-fourth  of  its  bulk 
of  alcohol.  Brandy,  rum,  and  whiskey,  contain  still  more 
alcohol.  Proof-spirit  is  half  water  and  half  alcohol. 

'8 


80 


CHEMIST!!  Y. 


The  alcohol  obtained  by  distillation  always  contains 
some  water,  from  which  that  operation  will  not  free  it; 
to  obtain  pure  alcohol,  therefore,  perfectly  dry  potass 
obtained  by  exposing  this  alkali  for  some  time  to  a  red 
heat,  is  put  into  it :  the  water,  having  a  stronger  affinity 
for  the  potass  than  for  the  alcohol,  combines  with  the 
alkali,  which  falls  to  the  bottom,  and  the  alcohol  may  bo 
drawn  off  with  the  siphon.  Afterwards  the  alcohol  should 
be  distilled  with  a  gentle  heat,  and  not  quite  to  dryness, 
that  any  potass  it  may  contain  may  be  left  behind. 

Alcohol  mixes  with  water  in  all  proportions,  and  the 
combination  is  so  intimate  that  the  mixture  takes  up  less 
space  than  the  fluids  separately;  and  therelore,  as  in 
every  other  combination  where  such  an  effect  happens, 
caloric  is  extricated,  and  may  be  felt  by  the  hand. 

Alcohol  is  the  grand  solvent  for  resins,  and  is  much 
used  for  making  varnishes.  Camphor  dissolves  in  it  very 
readily,  and  the  solution  hastens  that  of  some  substances 
upon  which  the  alcohol  alone  acts  but  slowly,  or  not  at 
all,  particularly  copal. 

Alcohol  takes  up  a  small  portion  of  phosphorus,  which 
is  precipitated  by  water.  Quicklime  alters  the  flavour 
of  alcohol,  and  renders  its  colour  yellow,  though  the 
earth  in  general,  and  metallic  oxides,  appear  to  have  no 
action  upon  it.  Both  fixed  and  essential  oils  are  soluble 
in  alcohol. 

The  composition  of  alcohol  is  not  accurately  known. 
The  analysis  of  Lavoisier  indicated  that  100  parts  of  it 
contain  of  carbon,  00,  of  hydrogen,  7.5,  and  of  water 
G2.5:  but  the  accuracy  of  the  analysis  is  doubtful;  for, 
as  it  was  conducted  by  burning  the  alcohol  in  oxygen, 
part  of  the  water  may  have  been  the  produce  of  com¬ 
bustion,  as  Fourcroy  and  Vauquelin  have  clearly  proved 
that  alcohol  contains  oxygen.  However  this  be,  the 
manner  in  which  the  component  paits  of  alcohol  are 
united,  remains  entirely  a  mystery. 

Betancourt  has  ascertained  the  important  fact,  that 
the  vapour  of  alcohol  has  more  than  double  the  expan¬ 
sive  force  of  that  of  water  of  the  same  temperature,  and 


ETHER. 


87 


that  die  steam  of  alcohol,  at  174°,  is  equal  to  that  of 
water  at  212°.  Hence,  it  has  been  suggested  that  alco¬ 
hol  may  be  employed  with  advantage  as  the  moving 
power  of  steam  engines,  with  a  great  saving  of  fuel,  and 
consequently,  of  expense,  when  means  shall  be  contrived 
to  save  the  fluid  from  being  lost. 

OF  ETHER. 

If  alcohol  be  mixed  with  its  own  weight  of  sulphuric 
acid,  gradually  added,  to  prevent  explosion,  and  the 
mixture  be  distilled  in  a  sand  bath,  the  first  product  ob¬ 
tained  is  alcohol,  but  afterwards  a  very  different  fluid, 
which  is  equal  in  quantity  to  half  the  alcohol  employed. 
This  fluid  is  called  ether. 

Ether  is  still  more  inflammable  and  volatile  than  alco¬ 
hol,  and  equally  as  colourless.  It  is  the  lightest  of  all 
known  fluids.  Its  smell  is  fragrant  and  agreeable,  but 
not  powerful.  Its  taste  is  hot  and  pungent.  Its  combus¬ 
tion  yields  a  blue  flame,  and  rather  more  smoke  than 
alcohol.  It  boils  at  98°.  It  may  be  obtained  of  the  spe¬ 
cific  gravity  of  .716. 

It  is  a  valuable  medicine  ;  being  used  externally  for 
the  headache  or  toothache,  by  pouring  a  little  upon  the 
hand  and  pressing  it  upon  the  forehead  or  cheek,  till  the 
pain  it  occasions  goes  ofl.  Its  internal  use  extends  to  all 
spasmodic  affections. 

The  nature  of  the  change  produced  on  alcohol  by  the 
acid,  when  ether  is  formed,  is  not  well  understood  ;  but 
it  is  supposed  that  ether  contains  a  much  larger  propor¬ 
tion  of  hydrogen  in  proportion  to  its  carbon. 

If  the  distillation  of  ether  be  continued  till  sulphurous 
vapours  appear,  and  the  recipient  be  then  changed,  a, 
new  product  is  obtained  ;  it  is  called  the  sweet  oil  of 
wine,  which  is  unctuous,  thick,  less  volatile  than  ethei ,  and 
of  a  yellow  colour.  The  last  product  obtained  by  urging 
the  fire,  is  sulphuric  acid  and  acetous  acid. 

Instead  of  the  sulphuric  acid,  ether  may  be  prepared 
with  the  nitric,  the  oxymuriatic,  the  acetic,  and  several 


CHEMISTRY. 


S8 

other  acids.  According  to  the  acid  employed,  its  proper¬ 
ties  differ  a  little:  nitric  ether  is  often  made,  but  the  sul¬ 
phuric  is  the  most  common  and  the  most  valued.  I  he 
peculiar  properties  of  the  ethers  made  with  different 
acids,  have  not  been  minutely  examined. 

Sulphuric  ether  acts  upon  most  resinous  substances;  it 
is  the  best  solvent  of  caoutchouc  ;  it  dissolves  also  the 
essential  oils  and  camphor;  mixes  in  all  proportions  with 
alcohol,  but  water  only  dissolves  a  tenth  of  it.  It  com 
bines  with  caustic  volatile  alkali ;  but  not  with  the  fixed 
alkalies  or  lime.  It  dissolves  a  little  sulphur  and  phos¬ 
phorus. 

If  the  ether  obtained  emit  a  sulphurous  odour,  it  must 
be  purified  by  a  second  distillation,  previous  to  which  it 
should  be  mixed  with  a  little  potass,  which  will  combine 
with  the  acid,  and  in  part  with  the  water. 

OF  METALS. 

The  metals,  from  their  extensive  and  diversified 
utility,  are  amongst  the  most  interesting  classes  of  sub 
stances  existing.  They  are  supposed  to  be  simple  bodies, 
and  not  a  single  fact  has  ever  been  ascertained  which 
shows  that  they  can  be  converted  into  each  ©'her;  yet, 
to  accomplish  this,  the  alchemists  exhausted  their  estates 
and  their  lives. 

The  metals  are  distinguished  by  their  possessing  all  or 
the  greater  part  of  the  following  properties;  hardness, 
tenacity,  lustre,  opacity,  fusibility,  malleability,  and  duc¬ 
tility  ;  and  they  are  excellent  conductors  of  caloric,  elec¬ 
tricity,  and  galvanism. 

Metals  are  generally  found  in  mountainous  countries. 
They  are  sometimes  met  with  in  a  state  of  purity, 
and  are  then  said  to  be  found  native:  but  they  are 
mostly  combined  with  other  substances;  and,  when  com¬ 
bined  in  such  quantities  as  to  be  worth  separating,  the 
substance  is  called  an  ore  of  the  metal  it  contains. 

All  the  metals  are  susceptible  of  crystallization.  'The 
easiest  mode  of  obtaining  their  crystalline  form,  is  to  let 


METALS. 


89 


out  the  middle  part  just  after  they  have  begun  to  con¬ 
geal  ;  the  interior  of  the  crust  thus  left  assumes  a  crys¬ 
talline  form. 

The  metals  are  fusible  at  very  different  temperatures; 
mercury,  for  example,  does  not  become  solid,  unless 
cooled  down  to  3!)°,  and  platina  is  not  softened  at  the 
heat  at  which  cast-iron  runs  like  water. 

Metals  differ  from  each  other  as  much  in  hardness  as 
in  fusibility.  Kirwan  has  adopted  a  very  simple  mode 
of  showing  their  comparative  hardness  by  figures.  We 
shall  adopt  his  plan,  which  he  thus  explains: 

3.  Denotes  the  hardness. of  chalk. 

4.  A  superior  hardness  ;  but  yet  what  yields  to  the 
nail. 

5.  What  will  not  yield  to  the  nail ;  but  easily,  and 
without  grittiness,  to  the  knife. 

G.  That  which  yields  with  more  difficulty  to  the  knife. 

7.  That  which  scarcely  yields  to  the  knife. 

8.  That  which  cannot  be  scraped  by  a  knife,  but  does 
not  give  fire  with  steel. 

9.  That  which  gives  a  few  feeble  sparks  with  steel. 

10.  That  which  gives  plentiful,  lively  sparks. 

Great  specific  gravity  was  formerly  considered  as  one 
of  the  chief  characteristics  of  the  metals,  the  lightest 
metal  being  twice  as  heavy  as  the  heaviest  body  of  any 
other  sort;  but  the  discovery  of  several  bodies,  which 
possess  all  the  characters  of  the  metals,  excepting  weight, 
and  which  cannot  therefore  be  omitted  in  the  list  of 
metals,  has  caused  great  specific  gravity  to  be  no  longer 

distinctive.  .... 

If  a  metal  be  exposed  to  a  heat  which  will  keep  it  in 
fusion,  it  may,  without  suffering  any  alteration  but  that 
of  its  figure,  (which  will  adapt  itself  to  the  vessel,)  be 
kept  any  length  of  time  in  that  state,  provided  the  access 
of  air  be  kept  entirely  from  its  surface.  But  it  the  fusion 
be  conducted  in  open  vessels,  the  surface  of  the  metal 
loses  its  metallic  brilliancy;  and  if  its  apparent  scum  be 
removed,  another  is  soon  formed,  until  the  whole  of  the 
metal  disappears,  and  instead  of  it  we  have  an  call  *y 
8  * 


90 


ClJF.MlSTJtY. 


opaque  powder  which  soils  the  hands.  Upon  collecting 
and  weighing  this  powder,  it  is  found  to  he  heavier  than 
the  metal  from  which  it  was  produced.  This  process 
was  by  the  ancient  chemists  called  calcination,  and  the 
product  of  it  was  called  a  calx;  they  knew  not  the 
cause  of  it,  and  were,  therefore,  wholly  unable  to  account 
for  the  increase  of  weight  which  they  obtained  by  it; 
but  the  moderns  having  thoroughly  investigated  the  sub¬ 
ject,  consider  all  metals  as  combustible  bodices ,  that  in 
the  operation  just  described  the  metal  has  suffered  com¬ 
bustion,  and  that,  therefore,  the  oxygen  of  the  atmos¬ 
phere  has  combined  with  it,  as  it  combines  with  all  other 
bodies  during  cojnbustion,  and  that  it  is  solely  fiom  the 
oxygen  absorbed  that  its  additional  weight  is  derived.  In 
proof  of  this,  they  find  by  suitable  experiments,  that  the 
oxygen  absorbed  is  exactly  equal  to  the  weight  acquired  ; 
ancTalso,  that  when  the  oxygen  is  taken  away,  by  pre¬ 
senting  some  substance  for  which  it  has  a  greater  affinity, 
the  metal  acquires  all  its  original  properties,  and  becomes 
of  the  same  weight  as  at  first.  Hence  for  the  vague 
term  calx,  the  modern  chemists  used  the  word  oxide,  to 
denote  the  earth-like  combinations  of  a  metal  with 
oxygen ;  and  the  act  or  process  in  which  this  change 
takes  place,  is  called  oxidation. 

Oxygen  will  not  combine  with  metals  in  all  propor 
tions,  as  acids  will  do  with  water,  but  only  in  one  or  two, 
or  at  most  a  few  proportions.  When  the  proportion 
of  oxygen  varies,  the  oxide  of  the  same  metal  assumes 
different  colours ;  the  colour  is  therefore  selected  to  dis¬ 
tinguish  these  differences.  Hence,  we  have  the  yellow 
oxide  of  lead,  the  red  oxide  of  lead,  dec.  \\  hen  the 
oxygen  which  converts  a  metal  into  an  oxide  is  supplied 
by  an  acid,  the  name  of  the  solvent,  as  well  as  the  colour 
of  the  oxide,  is  sometimes  given  :  thus  we  have  the  ivhite 

oxide  of  lead  by  the  acetous  acid. 

Some  of  the  metals  arc  so  much  disposed  to  oxidation, 
that  they  became  oxides  at  all  temperatures.  Iron  is  a 
metal  of  this  description '.  the  rust  to  which  it  cjianges  iD 
air  or  water  is  its  red  oxide. 


MKT  A  r,P. 


91 


If  the  oxide  of  a  metal  be  exposed  to  a  strong  heat,  it 
vitrifies,  or  is  converted  into  a  substance  resembling  com¬ 
mon  glass.  The  substances  employed  for  enamel  paint¬ 
ing,  for  colouring  glass,  and  for  glazing  earthenware,  are 
mostly  prepared  from  metallic  oxides. 

If  any  of  the  malleable  metals  be  hammered,  its  com¬ 
bined  caloric  becoming  sensible,  renders  it  hot,  and 
passes  otF  to  surrounding  bodies ;  the  metal  at  the  same 
time  is  rendered  denser,  harder,  more  rigid,  and  in  gene¬ 
ral  more  elastic.  A  portion  of  the  caloric,  to  which,  in 
common  with  other  bodies,  metals  owe  their  softness, 
appears  to  be  driven  out  of  it ;  for  its  former  state  re¬ 
turns  by  heating  it  to  ignition.  Rolling  produces  the 
same  etFcct  as  hammering. 

The  metals  combine  with  each  other,  and  besides 
oxygen,  with  the  simple  substances,  sulphur,  carbon,  and 
phosphorus.  When  two  metals  are  combined  together, 
the  mixture  is  called  an  alloy  of  that  metal  whose  weight 
predominates. 

Previous  to  the  year  1730,  only  eleven  metals  were 
known,  the  list  is  now  increased  to  forty-two  chiefly  by 
recent  discoveries,  and  the  probability  is  very  strong,  that 
there  exists  a  much  larger  number.  The  metals  may  be 
divided  into  two  classes; — the  malleable  and  the  brittle; 
the  brittle  metals  may  be  further  subdivided  into  those 
which  are  easily  fused,  and  those  which  arc  fused  with 
difficulty.  We  shall  enumerate  them,  in  each  of  these 
classes,  in  the  order  of  their  specific  gravity. 


1.  Malleable  Metals. 


1.  Platina, 

2.  Gold, 

3.  Mercury, 

4.  Lead, 

5.  Palladium, 

6.  Silver, 

7.  Nickel, 


8.  Copper, 

9.  Iron,  . 

10.  Tin, 

11.  Zinc, 

12.  Sodium, 

13.  Potassium. 


2.  Brittle  Metals,  f  used  without  difficulty. 

1.  Bismuth,  3  Antimony, 

2.  Arsenic,  4.  Tellurium. 


92 


CIir.MISTR  y  . 


Brittle  Metals,  of  difficult  fusion. 


1.  Tungsten, 

2.  Uranium, 

3.  Rhodium, 

4.  Cobalt, 


8.  Titanium, 

0.  Chromium, 

10.  Columbium, 


5.  Molybdenum, 
G.  Manganese, 

7.  Tantalium, 


1 1.  Cerium, 

12.  Osmium, 

13.  Iridium 


PLATINA. 


The  specific  gravity  of  platina,  after  hammeiing,  i* 
23,000.  It,  therefore,  holds  the  pre-eminence  of  all 
bodies  in  point  of  weight,  and  it  has  other  extraordinary 
properties. 

It  is  incapable  of  tarnishing  by  exposure  to  the  an 
The  strongest  mineral  acids  have  no  effect  upon  it,  if 
employed  separately,  nor  will  the  strongest  fire  melt  it, 
unless  urged  by  oxygen  gas  ;  a  crucible  of  it  not  thicker 
than  a  sheet  of  paper,  will  endure  the  heat  of  the  best 
furnace,  and  come  out  unaltered.  When  intensely  heat¬ 
ed,  it  possesses,  like  iron,  the  property  of  welding,  but 
the  labour  of  working  it  is  very  great.  Its  hardness  is 
7.5.  Its  colour  is  between  that  of  iron  and  silver. 

Platina  was  unknown  in  Europe  before  the  year  1741. 
when  a  quantity  of  it  was  brought  by  Charles  Wood, 
from  Jamaica.  It  was  supposed  only  to  be  found  in  the 
gold  mines  in  Peru,  but  Vauquelin  has  met  with  it  in 
Spain,  in  the  mines  of  Guadalcanal.  Its  name,  in  the 
language  of  Peru,  signifies  little  silver,  and  on  its  gieat 
specific  gravity  being  ascertained,  attempts  have  been 
made  to  prevent  its  use,  lest  gold  should  be  adulterated 
with  it.  It  has  never  been  met  with  except  in  the 
metallic  state,  in  the  form  of  smooth  grains  of  all  sizes 
up  to  that  of  a  pea,  but  very  seldom  larger. 

Platina  may  be  fused  by  a  powerful  burning-glass : 
but  its  total  infusibility  by  ordinary  means,  has  caused 
various  processes  to  be  resorted  to,  for  obtaining  it  in  a 
solid,  malleable  state.  For  this  purpose  it  must  be  dissol 


93 


1’ LATIN  A. 

(  I  in  an  acid  ;  oxymuriatic  acid,  and  nitromuriatic  acid 
b\  di  dissolve  it.  The  latter  acid  should  consist  of  one 
part  of  nitric,  and  three  of  muriatic  acid.  I  he  solution 
is  very  corrosive,  and  tinges  animal  substances  ol  <«  J  ac  c 
ish  brown  colour ;  it  affords  crystals  by  evaporation. 
Count  Moussin  Pouschin  directs  malleable  platina  to  be 
prepared  from  its  solution  as  follows:  Precipitate  the 
platina  by  adding  a  solution  of  muriate  of  ammonia,  ana 
wash  the  precipitate  with  a  little  cold  water.  It  is 
red-coloured,  which  distinguishes  this  metal  from  gold, 
lleduce  it  in  a  convenient  crucible  to  the  well-known 
spongy  metallic  texture,  wash  the  mass  obtained  two  or 
three  times  in  boiling  water,  to  carry  oil  any  portion  ot 
saline  matter  that  may  have  escaped  the  action  ot  the 
fire.  Boil  it  in  a  glass  vessel  for  about  half  an  hour,  in 
as  much  water  mixed  with  one-tenth  of  muriatic  acid, 
as  will  cover  it  about  half  an  inch.  This  will  carry  oil 
the  iron  that  might  exist  in  the  metal.  Decant  the  acid 
water,  and  edulcorate  or  strongly  ignite  the  platina.  lo 
one  part  of  this  metal  take  two  parts  of  mercury,  and 
amalgamate  in  a  glass  or  porphyry  mortar.  1  his  amal¬ 
gamation  takes  place  very  readily.  1  lie  proper  method 
of  conducting  it,  is  to  take  about  two  drachms  of  mercury 
to  three  of  platina,  and  amalgamate  them  together,  and 
to  this  amalgam  may  be  added  alternate  small  quantities 
of  platina  and  mercury,  till  the  whole  of  the  two  metals 
is  combined.  Several  pounds  may  thus  be  amalgamated 
in  a  few  hours,  and  in  the  large  way,  a  mill  might  short¬ 
en  the  operation.  As  soon  as  the  amalgam  of  mercury 
is  made,  compress  it  in  tubes  of  wood,  by  the  pressure  of 
an  iron  screw  upon  a  cylinder  of  wood  adapted  to  the 
bore  of  the  tube.  This  forces  the  superabundant  mer¬ 
cury  from  the  amalgam,  and  renders  it  solid.  After  two 
or  three  hours,  burn  upon  the  coals,  or  in  a  crucible  lined 
with  charcoal,  the  sheath,  in  which  the  amalgam  is  con¬ 
tained,  and  urge  the  fire  to  a  white  heat  ;  after  which 
the  platina  may  be  taken  out  in  a  very  solid  state,  tit  to 

bCThe  ductility  of  platina  is  such,  that  it  has  been  drawn 


94 


CHEMISTRY. 


into  wire  of  less  than  the  two-thousandth  part  of  an  inch 
in  diameter.  This  wire  admits  of  being  flattened,  and 
is  stronger  than  that  of  gold  or  silver,  of  the  same  thick¬ 
ness. 

Platina  will  not  combine  with  gold,  except  in  a  violent 
heat.  When  not  more  than  one  forty-seventh  of  the  al¬ 
loy  is  platina,  the  gold  is  not  perceptibly  altered  in  colour; 
but,  if  the  proportion  be  materially  greater,  the  paleness 
of  the  gold  betrays  its  impurity.  Added  in  the  proportion 
of  one-twelfth  to  gold,  it  forms  a  yellowish-white  metal, 
highly  ductile,  and  so  elastic,  that  Hatchett  supposed  it 
might  be  used  for  watch-springs,  and  other  purposes.  Its 
specific  gravity  was  19.013. 

It  also  requires  a  violent  heat  to  make  platina  and 
silver  combine;  the  silver  becomes  less  white  and  duc¬ 
tile,  but  harder.  If  the  two  metals  be  kept  for  some 
time  in  fusion,  they  separate,  and  the  platina,  from  it? 
greater  weight,  sinks  to  the  bottom. 

The  alloy  of  copper  and  platina  is  hard,  yet  ductile, 
while  the  copper  is  in  proportion  of  three  or  four  parts 
to  one.  This  alloy  is  not  liable  to  tarnish,  especially 
when  the  platina  predominates;  and  it  is,  therefore,  ex¬ 
cellent  for  the  specula  of  reflecting  telescopes,  as  platina 
takes  an  excellent  polish,  and  reflects  a  single  image. 
The  addition  of  a  little  arsenic  improves  this  alloy.  But 
copper  is  much  improved  in  colour,  grain,  and  suscepti¬ 
bility  of  polish,  when  the  platina  is  only  in  proportion  of 
a  tenth  or  fifteenth. 

Alloys  of  platina  with  tin  or  lead  are  very  apt  to  tar¬ 
nish  ;  that  with  lead  is  formed  at  the  strongest  heat :  it 
is  not  ductile,  and  the  lead  is  not  absorbed  by  the  cupel, 
unless  it  is  in  excess ;  and  even  then,  the  separation  of 
the  lead  is  not  complete. 

Platina  unites  easily  with  tin;  the  alloy  is  very  fusi- 
ble,  but  its  grain  is  coarse  and  brittle.  It  is  ductile, 
when  the  proportion  of  tin  is  large:  it  becomes  yellow 
by  exposure  to  the  air. 

Zinc  renders  platina  more  fusible,  and  forms  with  it  a 
very  hard  alloy  The  zinc  cannot  be  entirely  separated 
bv  heat 


METALS. 


95 


Bismuth  and  antimony  likewise  facilitate  the  fusion 
of  platina,  with  which  they  form  brittle  alloys,  and  are 
not  wholly  separated  by  heat.  Arsenic  has  the  same 
effect  as  these  metals  in  promoting  its  fusion. 

Platina  has  not  been  united  to  forged  iron  ;  but  with 
cast  iron,  it  forms  an  alloy  which  resists  the  file. 

If  phosphorus  be  thrown  upon  red-hot  platina,  the 
metal  is  fused,  and  forms  a  phosphuret,  which  is  of  a 
silvery  white,  very  brittle,  and  hard  enough  to  strike 
fire  with  steel.  As  heat  expels  the  phosphorus,  Pollitier 
proposed  this  as  an  easy  method  of  purifying  platina ; 
but  he  afterwards  found  that  the  last  portions  of  phos¬ 
phorus  were  retained  by  too  strong  an  affinity. 

Several  of  the  metallic  salts  decompose  the  solution 
of  muriate  of  platina.  Muriate  of  tin  is  so  delicate  a. 
test  of  it,  that  a  single  drop,  recently  prepared,  gives  a 
bright  red  colour  to  muriate  of  platina,  which  before 
this  addition,  is  so  clear  as  to  be  scarcely  distinguished 
from  water. 

If  nitro-muriatic  solution  of  platina  be  precipitated  by 
lime,  and  the  precipitate  digested  in  sulphuric  acid,  a  sul¬ 
phate  of  platina  will  be  formed.  A  sub-nitrate  may  be 
formed  in  the -same  way. 

Platina  does  not  form  a  direct  combination  with  sul 
phur,  but  is  soluble  by  the  alkaline  sulphurets,  and  pre¬ 
cipitated  from  its  nitro-muriatic  solution  by  sulphuretted 
hydrogen. 

The  fixedness  of  platina  admirably  fits  it  for  crucibles, 
and  many  other  chemical  utensils,  which  may  be  made 
thinner  of  this  than  of  any  other  material  whatever. 
It  is,  however,  besides  the  disadvantages  of  its  expense, 
liable  to  corrosion  from  caustic  alkalies,  and  some  of  the 
neutral  salts. 

If  either  be  mixed  and  agitated  with  the  nitro-muri¬ 
atic  solution  of  platina,  it  takes  up  the  metal ;  and,  as  it 
will  soon  float  on  the  surface  of  the  solution,  it  may  be 
poured  off,  and,  if  brushed  over  the  clean  surface  of  any 
other  metal,  it  will  soon  evaporate,  and  impart  to  them 
a  coating  of  platina. 


96 


CHEMISTRY. 


GOLD. 

Gold  is  the  most  malleable,  ductile,  and  most  brilliant 
nf  an  the  metallic  substances;  and,  next  to  platina,  the 
heaviest  and  most  indestructible. 

Gold  is  seldom  found  except  in  the  metallic  state.  It 
has  been  obtained  in  every  quarter,  and  almost  every 
country  of  the  globe;  but  South  America  supplies  a 
greater  quantity  than  all  the  rest  of  the  world. 

Many  laborious  experiments  have  been  repeatedly 
made  by  able  chemists,  who  appear  to  have  established 
the  fact,  that  gold  exists  in  vegetables. 

A  single  grain  of  gold  can  be  made  to  cover  an  area 
of  more  than  400  square  inches;  a  wire  of  one-tenth  of 
an  inch  in  diameter  will  support  a  weight  of  500  pounds; 
and  Dr.  Black  has  calculated  that  it  would  take  fourteen 
millions  of  films  of  gold,  such  as  cover  some  fine  gilt 
wire,  to  make  up  the  thickness  of  an  inch  ;  whereas  the 
same  number  of  leaves  of  common  writing  paper  would 
make  up  nearly  three  quarters.of  a  mile. 

Though  opacity  is  enumerated  as  one  of  the  charac¬ 
ters  of  the  metals,  yet  gold,  when  the  ■jiroVo'TiIh  of  an 
inch  thick,  which  is  about  the  thickness  of  ordinary  gold 
leaf,  transmits  light  of  a  lively  bluish  green  colour.  1  er- 
haps  all  the  other  metals,  if  they  could  be  equally 
extended,  would  show  some  degree  ot  transparency,  but 
none  of  them  can  be  made  so  thin. 

The  specific  gravity  of  unhammered  gold,  is  19.258, 
and  is  increased  but  little  by  hammering.  Its  hardness 
is  C.  It  melts  at  32°,  of  Wedgwood;  and  if  pure,  its 
colour  when  in  fusion  is  not  yellow,  but  a  beautiful 
bluish  green,  like  the  light  which  it  transmits. 

Gold  cannot  be  volatilized,  except  at  an  extreme  heat. 
The  utmost  power  of  Parker’s  celebrated  burning  lens 
exerted  upon  it  for  some  hours,  did  not  cause  it  to  lose 
any  weight  which  could  be  discovered;  but  Lavoisier 
found  that  a  piece  of  silver,  held  over  gold  melted  by  a 
lire  maintained  with  oxygen  gas,  was  sensibly  gilt :  and 
perhaps  the  same  delicate  test  would  have  shown  its 
volatility  by  the  lens. 


GOLD. 


97 


After  fusion,  gold  will  assume  the  crystalline  form. 
Tillet  and  Mongez  obtained  it  in  short  quadrangular 
pyramidal  crystals. 

Gold  unites  with  most  of  the  metals.  Silver  renders 
it  pale ;  when  the  proportion  of  silver  is  about  one-fifth 
part,  the  alloy  has  a  greenish  hue.  Silver  separates 
from  gold  as  from  platina,  if  the  alloy  be  kept  for  some 
time  in  fusion. 

Gold  is  strongly  disposed  to  unite  with  mercury ;  this 
alloy  forms  an  amalgam,  the  softness  of  which  is  in  pro¬ 
portion  to  the  quantity  of  mercury.  It  is  by  mercury, 
that  in  South  America,  gold  is  chiefly  obtained  from  the 
earth  with  which  it  is  mixed,  and  the  gold  is  separated 
by  distillation.  This  alloy  readily  crystallizes  after  fusion. 
It  is  applied  by  gilders  to  the  surface  of  clean  copper, 
and  the  mercury  is  driven  off  by  heal. 

Gold  unites  freely  with  tin  and  lead,  but  both  these 
metals  impair  its  ductility.  Of  lead,  one  quarter  of  a 
grain  to  the  ounce  renders  the  gold  brittle ;  but  tin  has 
not  so  remarkable  an  effect. 

Copper  increases  the  fusibility  of  gold,  as  well  as  its 
hardness,  and  deepens  its  colour.  It  forms  the  usual 
addition  to  gold  for  coin,  plate,  &c.  The  standard  gold 
of  Great  Britain  is  twenty-two  parts  pure  gold,  and  two 
parts  copper ;  it  is,  therefore,  called  “  gold  of  twenty- 
two  carats  fire.” 

Iron  forms  an  alloy  with  gold,  so  hartjl  as  to  be  fit  for 
edge  tools.  Its  colour  is  grey,  and  it  obeys  the  magnet. 

Arsenic,  bismuth,  nickel,  manganese,  zinc,  and  anti¬ 
mony,  render  gold  white  and  brittle.  When  the  alloy  is 
with  zinc  in  equal  proportions,  it  has  a  fine  grain,  takes 
a  high  polish,  and  from  these  qualities,  and  its  being  not 
liable  to  tarnish,  it  forms  a  composition  not  unsuitable  for 
the  mirrors  of  telescopes. 

For  the  purpose  of  coin,  Hatchett  considers  an  alloy 
consisting  of  equal  parts  of  silver  and  copper  as  the  best, 
and  copper  alone  as  preferable  to  silver.  The  same  dis¬ 
tinguished  chemist  gives  the  following  order  of  different 
metals,  arranged  as  they  diminish  the  ductility  of  gold: 
U  ' 


CHEMISTRY. 


98 

viz.  Bismuth,  lead,  antimony,  arsemc,  zinc,  cobalt,  manga 
nese,  nickel,  tin,  iron,  platina,  ccpper,  silver.  The  first 
three  were  nearly  equal  in  effect,  but  the  platina  was 
not  quite  pure. 

The  nitric  acid  will  take  up  a  very  minute  quantity 
of  gold,  but  the  nitro-muriatic  and  oxy-muriatic  acids 
are  its  only  real  solvents.  The  two  latter  acids  are  of  a 
similar  nature,  and  their  effects  on  gold  are  increased  by 
concentrating  them,  by  enlarging  the  surface  of  the  gold 
and  by  the  application  of  heat.  The  solution  is  of  a 
yellow  colour,  caustic,  and  tinges  the  skin  of  a  deep  pur¬ 
ple.  By  evaporation  it  affords  yellow  crvstals,  which 
take  the  form  of  truncated  octahedrons.  These  crystals 
are  a  muriate  of  gold ;  they  may  be  dissolved  in  water, 
and  will  stain  the  skin  in  the  same  manner  as  the  acid. 

Most  metallic  substances  precipitate  gold  from  its  solu¬ 
tion  in  the  nitromuriatic  acid  :  lead,  iron,  and  silver, 
precipitate  it  of  a  deep  and  dull  purple  colour  ;  copper 
and  iron  throw  it  down  in  its  metallic  state;  bismuth, 
zinc,  and  mercury,  likewise  precipitate  it.  \\  hen  pre¬ 
cipitated  by  tin,  it  forms  the  purple  precipitate  of  Cassius, 
which  is  much  used  by  enamellers  and  manufacturers  oi 
porcelain. 

Ether,  naphtha,  and  essential  oils,  take  gold  from  its 
solvent,  and  from  liquors  which  have  been  called  potable 
gold,  and  are  used  in  gilding.  The  gold  obtained  irom 
these  fluids  by  evaporation,  is  extremely  pure. 

If  diluted  nitromuriatic  solution  of  gold  be  used  to 
write  with  upon  any  substance,  and  the  letters  while  yet 
moist,  be  afterwards  exposed  to  a  stream  of  hydrogen  gas, 
the  gold  will  he  revived,  and  the  substance  will  appear 
gilt.  Ribbons  may  be  gilt  in  this  manner.  Sulphurous 
acid  gas  revives  the  gold  in  the  same  manner. 

Lime  and  magnesia  precipitate  gold  from  its  solution 
in  the  form  of  a  yeflowish  powder.  Alkalies  do  the  same, 
but  an  excess  of  alkali  re-dissolves  the  precipitate.  The 
precipitate  ob*a.ned  by  means  of  a  fixed  alkali  appears 
to  be  a  true  oxide  ;  it  is  taken  up  by  the  sulphuric,  nitric, 
and  muriatU  cids,  but  separates  by  standing  with  cry.v 


GOLD. 


99 


tallizing.  The  precipitate  by  gallic  acid  is  of  a  reddish 
colour,  and  very  soluble  in  the  nitric  acid,  to  which  it 
communicates  a  blue  colour. 

Gold  precipitated  from  its  yellow  solution  by  ammoniac, 
forms  a  powder  called  fulminat ing  gold  ;  this  dangerous 
compound  detonates  by  friction,  or  a  very  gentle  heat. 
It  cannot  be  prepared  or  preserved  without  great  risk. 
Macquer  gives  an  instance  of  a  person  who  lost  both 
eyes  by  the  bursting  of  a  bottle  containing  some  of  it ; 
and  which  exploded  by  the  friction  of  the  glass-stopper 
against  an  unobserved  grain  of  it  in  the  neck  of  the 
bottle. 

Green  sulphate  of  iron  precipitates  gold  of  a  brown 
colour;  but  this  soon  changes  to  the  colour  of  gold. 

The  alkaline  sulphurets  precipitate  gold  from  its  solu¬ 
tion  ;  the  alkali  unites  with  the  acid,  and  the  gold  falls 
down  combined  with  the  sulphur.  The  sulphur  may  be 
expelled  by  heat. 

The  alkaline  sulphurets  will  also  dissolve  gold.  Thus, 
if  equal  parts  of  sulphur  and  potass,  with  one-eighth  of 
their  joint  weight  of  gold  in  leaves,  be  fused  together, 
the  mixture,  when  poured  out  and  pulverized,  will  dis¬ 
solve  in  hot  water,  to  /which  it  gives  a  yellowish  green 
hue.  Stahl  wrote  a  dissertation  to  prove  that  Moses 
dissolved  the  golden  calf  in  this  manner. 

Sulphur  alone  has  no  effect  on  .gold.  The  process 
called  dry-parting  is  founded  upon  this  circumstance. 
This  is  used  for  separating  a  small  quantity  of  gold  from 
a  large  quantity  of  silver.  The  alloy  is  fused,  and  flow¬ 
ers  of  sulphur  are  thrown  upon  its  surface  ;  the  sulphur 
reduces  the  greater  part  of  the  silver  to  a  black  scoria. 
The  small  remainder  of  the  silver  may  now  be  separated 
by  solution  in  nitric  acid.  The  advantage  of  the  opera¬ 
tion  consists  in  saving  the  large  quantity  of  nitric  acid 
which  would  have  been  required  to  dissolve  the  silver  of 
the  alloy  in  its  original  state. 

The  heat  produced  by  the  electro-galvanic  discharge 
reduces  gold  to  the  state  of  a  purple  oxide. 


100 


CHEMISTRY. 


MERCURY. 

Mercury  is  distinguished  from  all  other  metals,  by  its 
fluidity  at  the  common  temperature  of  the  atmosphere 
Its  colour  is  white,  and  its  surface  is  like  that  of  polished 
silver.  Its  speciflc  gravity  is  13.580;  and  it  is,  there¬ 
fore,  the  heaviest  of  all  substances,  except  platina  and 
gold. 

Mercury  boils  at  G55 ;  and  does  not  cease  to  be  a 
fluid,  unless  at  or  below  the  temperature  of  — 39°.  In 
Russia,  and  Hudson’s  Bay,  this  temperature  sometimes 
occurs  naturally ;  it  may,  however,  be  obtained  by  a 
freezing  mixture.  Mercury  has  then  been  examined, 
and  found  to  be  perfectly  malleable,  working  like  soft 
tin.  Experiments  with  artificial  cold  afford  but  few  op¬ 
portunities  for  exhibiting  this  property  ;  but  at  Hudson’s 
Bay,  where  surrounding  objects  were  all  equally  cold, 
frozen  mercury  has  been  beaten  upon  an  anvil  into  sheets 
as  thin  as  paper.  A  mass  of  it,  being  thrown  into  a 
glass  of  warm  water,  became  fluid,  but  the  water  was 
immediately  frozen,  and  the  glass  shivered  to  pieces. 
To  the  touch,  frozen  mercury  excites  the  same  sensation 
as  red-hot  iron. 

Mercury  is  frequently  obtained  from  the  mines  in  the 
pure  metallic  state;  sometimes  it  is  combined  with  silver, 
but  mostly  with  sulphur,  in  combination  with  which  it 
is  called  cinnabar,  when  the  mixture  is  of  a  red  colour, 
but  Ethiop’s  mineral,  when  it  is  black.  I  hese  are  both 
sulphurets  of  mercury.  Mercury  is  supplied  by  many 
countries.  The  mines  of  Idria,  in  the  circle  of  lower 
Austria,  have  been  wrought  for  300  years,  and  are  esti¬ 
mated  to  yield  100  tons  annually.  From  Spain,  which 
supplies  large  quantities,  it  is  exported  to  South  America 
for  amalgamating  with  gold;  for  which  use,  the  consump¬ 
tion  is  so  prodigious,  that  the  mine  of  Guanca  \  elica, 
in  Peru,  does  not  supply  enough.  This  mine  is  a  vast 
cavern,  170  fathoms  in  circumference,  and  480  fathoms 

deep.  ...  .  , 

Cinnabar,  to  obtain  the  metal  from  it,  is  mixed  wit.i 


MERCURY. 


101 


quick-lime,  and  then  submitted  to  heat.  The  lime  com¬ 
bines  with  the  sulphur,  and  the  mercury  which  sublime? 
from  the  mixture  is  collected  in  receivers.  Mercury  sub¬ 
limes  at  the  heat  of  G00°,  and  then  has  the  appearance 
of  a  white  smoke.  In  this  state  of  vapour,  its  elasticity 
renders  it  capable  of  bursting  the  strongest  vessels,  if  the 
attempt  be  made  to  resist  its  expansion.  Distillation  is 
the  ordinary  means  of  purifying  mercury. 

Mercury  combines  very  freely  with  gold,  silver,  lead, 
tin,  bismuth,  and  zinc  ;  not  so  freely  with  copper,  arse¬ 
nic,  and  antimony  ;  for  iron,  its  affinity  is  extremely 
slight,  and  less  so  still,  if  possible,  for  platina. 

The  alloy  of  mercury  with  any  metal,  if  the  mercury 
predominates  so  far  as  to  render  it  soft,  and  of  the  con¬ 
sistence  of  butter,  is  called  an  amalgam.  These  amal¬ 
gams  are  much  employed  in  silvering  and  gilding,  as  the 
mercury  is  easily  driven  off  by  heat,  and  the  fixed  metal 
is  left  behind.  The  metal  with  which  the  backs  of 
looking-glasses  are  coated,  is  an  amalgam  of  tin  and 
mercury. 

The  number  of  metals  with  which  mercury  combines, 
renders  it  extremely  liable  to  adulteration.  The  union 
is  in  some  cases  so  strong,  that  the  baser  metal  will  rise 
along  with  it  in  distillation.  The  experienced  eye  can, 
however,  determine  very  small  adulterations,  by  the  want 
of  perfect  fluidity  and  brightness.  Impure  mercury  alsc 
soils  white  paper,  and  the  presence  of  lead  may  be 
detected  by  agitating  the  metal  with  water,  by  which 
means  it  will  be  oxidized.  Or  a  very  minute  quantity 
of  lead,  present  in  a  large  quantity  of  mercury,  may  be 
detected  by  solution  in  nitric  acid,  and  the  addition  of 
sulphuretted  water.  A  dark  brown  precipitate  will 
ensue,  and  will  subside  in  the  course  of  a  few  days.  One 
part  of  lead  may  be  thus  separated  from  15,263  parts  of 
mercury.  Bismuth  is  detected  by  pouring  a  nitric  solu¬ 
tion,  prepared  without  heat,  into  distilled  water ;  this 
metal  will  be  separated  in  the  form  of  a  white  precipi¬ 
tate.  If  tin  be  present,  a  weak  solution  of  muriate  of 
gold  will  cause  a  purple  precipitate. 

9* 


CHEMISTRY. 


102 

By  agitating  mercury  for  some  time  in  oxygen  oi 
atmospheric  air,  a  part  of  it  is  converted  into  a  blac* 
oxide. 

Most  of  the  acids  have  more  or  less  action  on  mercury 
The  sulphuric  acid  requires  the  assistance  ot  heat,  anu 
sulphurous  acid  gas  is  disengaged  during  its  action,  and 
a  white  oxide  is  formed,  which  becomes  yellow  by  pour¬ 
ing  hot  water  upon  it,  and  is  then  called  turbith  mineral ; 
it  is  a  subsulphate  of  mercury;  the  water  holds  in  solu¬ 
tion  sulphate  of  mercury. 

The  nitric  acid  dissolves  mercury  rapidly  without  heat ; 
nitrous  gas  is  disengaged,  and  the  colour  of  the  acid  at 
the  same  time  becomes  green.  If  the  acid  be  strong,  it 
will  take  up  its  own  weight  of  mercury  in  the  cold,  and 
will  bear  dilution  ;  heat  will  enable  the  acid  to  dissolve 
much  more  of  the  metal,  and  the  addition  of  distilled 
water  will  form  a  precipitate,  which  is  yellow  if  the 
water  be  hot,  and  white  if  it  be  cold.  This,  from  its 
resemblance  to  the  turbith  mineral  mentioned  above,  is 
called  nitrous  turbith. 

All  the  combinations  of  mercury  with  nitric  acid  are 
strongly  caustic,  and  form  a  deep  black  or  purple  spot  on 
the  skin.  When  nitrate  of  mercury  is  exposed  to  a 
gradual  and  long  continued  low  heat,  it  gives  out  a  por¬ 
tion  of  nitric  acid,  and  is  converted  into  a  bright  red 
oxide  ;  this  oxide  retains  a  small  portion  of  nitric  acid ; 
it  is  called  red.  precipitate,  which  is  employed  in  medi¬ 
cine  as  a  caustic.  This  red  oxide  parts  with  its  oxygen 
simply  by  heat,  and  the  mercury  recovers  its  metallic 
state.  The  finest  precipitate  is  made,  by  distilling  the 
mercurial  solution  till  no  more  vapour  arises;  then  add¬ 
ing  several  successive  portions  of  abid,  and  distilling  it 
dry  after  each  addition.  The  precipitate  will  thus  be 
obtained  in  small  crystals  of  a  supei  b  red  colour.  Red 
precipitate  may  be  prepared  by  heat  only :  the  mercury 
must  for  this  purpose  be  kept  at  the  heat  ot  about  000° 
for  several  months ;  the  red  oxide  thus  formed  was  called 
'precipitate  per  se. 

The  acids,  the  alkalies,  the  earths,  and  most  of  the 


MRRCUIIY. 


103 


metals,  precipitate  mercury  from  its  olution  in  the  nitric 
acid.  The  precipitates  by  alkalies  have  the  property  of 
exploding,  if  triturated  with  one-sixth  of  their  weight  of 
flowers  of  sulphur,  and  afterwards  gradually  heated. 

The  muriatic  acid  does  not  act  on  mercury,  except  by 
long  digestion,  which  enables  it  to  oxidize  a  part,  and  it 
dissolves  the  oxide.  This  acid,  however,  completely  dis¬ 
solves  the  mercurial  oxides,  which,  when  nearly  in  the 
metallic  state,  or  containing  but  little  oxygen,  form  the 
muriate  of  mercury.  When  the  oxy-muriatic  acid  is 
employed,  the  oxy-muricite  of  mercury,  or  corrosive  sub- 
imate ,  is  formed.  Corrosive  sublimate  is  highly  caustic  . 
and  poisonous. 

Sulphur  readily  combines  with  mercury.  If  triturated 
with  this  metal  in  a* mortar,  it  forms  with  it  a  black  sul- 
phuret,  formerly  called  ethiop’s  mineral.  This  compound 
may  also  be  formed  by  adding  to  sulphur  in  fusion  one 
fourth  of  its  weight  of  mercury. 

If  ethiops  mineral,  or  black  sulphuret  of  mercury,  be 
sublimed,  it  alfords  the  red  sulphuretted  oxide,  or  artificial 
cinnabar.  This  cinnabar,  when  pounded  and  washed 
for  painters’  use,  is  called- vermilion.  To  prepare  it  with 
accuracy,  let  300  grains  of  mercury  and  08  of  sulphur, 
with  a  few  drops  of  solution  of  potass  to  moisten  them, 
be  triturated  in  a  porcelain  mortar,  with  a  glass  pestle, 
till  converted  to  the  state  of  black  oxide.  Add  to  this 
100  grains  of  potass,  dissolved  in  as  much  water.  Heat 
the  vessel  containing  the  ingredients  over  the  flame  of 
a  candle,  and  continue  the  trituration  without  inter¬ 
ruption  during  the  heating.  In  proportion  as  the  liquid 
evaporates,  add  clear  water  from  time  to  time,  so  that 
the  oxide  may  be  constantly  covered  to  the  depth  of 
near  an  inch.  The  trituration  must  be  continued  about 
two  hours;  at  the  end  of  which  time  the  mixture  begins 
to  change.from  its  original  black  colour  to  a  brown,  which 
usually  happens  when  a  large  part  of  the  fluid  is  evapo¬ 
rated.  It  then  passes  very  rapidly  to  a  red.  No  more 
water  is  then  to  be  added,  but  the  trituration  is  to  be  con¬ 
tinued  without  interruption.  When  the  mass  has  acquired 


CHEMISTRY. 


104 

the  consistence  of  a  jelly,  the  red  colour  increases  in 
brightness  with  surprising  rapidity.  1  he  instant  the 
colour  has  acquired  its  utmost  beauty,  the  heat  must  be 
withdrawn,  otherwise  the  red  passes  to  a  dirty  brown. 
This  is  KirchotPs  method  of  preparing  vermilion.  Count 
Moussin  Pouschin  discovered  that  the  brown  colour  may 
be  prevented  by  taking  the  sulphuret  from  the  hre  as 
soon  as  it  begins  to  be  red,  and  placing  it  in  a  gentle  heat, 
taking  care  to  add  a  few  drops  of  water,  and  to  agitate 
the  mixture  from  time  to  time.  By  this  treatment  an 
excellent  red  is  obtained. 

Phosphorus,  mixed  with  red  oxide  of  mercury,  and 
distilled,  forms  a  phosphuret  of  mercury ,  which  is  of  a 
black  colour,  and  in  the  air  exhales  phosphoric  vapour. 

% 

PALLADIUM. 

Palladium  is  of  a  greyish  white  colour,  scarcely  dis¬ 
tinguishable  from  platina,  and  takes  a  good  polish.  It  is 
ductile,  and  very  malleable ;  flexible,  when  reduced  to 
thin  slips,  but  not  very  elastic.  Its  fracture  is  fibrous, 
and  in  diverging  striae,  showing  a  kind  ot  crystalline  ar¬ 
rangement.  It  is  harder  than  wrought  iron.  Its  specific 
gravity  is  about  10.0,  but  mav  be  increased  bv  hammer¬ 
ing  and  rolling  to  11.8.  It  is  a  less  perfect  conductor  ot 
caloric  than  the  other  metals,  and  less  expansible,  though 
in  this  respect  it  exceeds  platina. 

Palladium  was  discovered  by  Dr.  Wollaston  in  native 
platina.  When  exposed  to  a  strong  heat,  its  surface  tar¬ 
nishes  a  little,  and  becomes  blue;  but  by  increasing  the 
heat,  it  becomes  briuht.  By  an  intense  heat,  it  is  fuse*  , 
but  not  oxidized.  Its  oxides,  formed  by  means  of  acids, 
may  be  reduced  by  heat  alone. 

Palladium  may  be  obtained  by  adding  to  nitro-mun- 
atic  solution  of  crude  platina,  a  solution  of  prussiate  of 
mercury,  on  which  a  flaky  precipitate  will  gradually  be 
formed,  of  a  yellowish  white  colour.  1  his  is  prussiate 
of  palladium,  from  which  the  acid  may  be  expelled  by 
heat 


PALLADIUM. 


105 


The  sulphuric,  the  nitric,  and  the  muriatic  acids  dis¬ 
solve  a  small  portion  of  palladium,  and  acquire  by  it  a 
red  colour.  The  nitro-muriatic  dissolves  it  rapidly,  and 
acquires  a  deep  red. 

Alkalies  and  earths  precipitate  palladium  from  its  so¬ 
lutions,  generally  of  a  tine  orange  colour ;  an  excess  of 
alkali  partly  re-dissolves  the  precipitate. 

Alkalies  act  upon  metallic  palladium;  and  this  action 
is  assisted  by  the  contact  of  air. 

Green  sulphate  of  iron  precipitates  palladium  in  a  me¬ 
tallic  state;  and  all  the  metals,  except  gold,  silver,  and 
platina,  do  the  same.  Prussiate  of  mercury  produces  a 
yellowish  white  precipitate;  and,  as  it  does  not  precipi¬ 
tate  platina,  it  is  an  excellent  test  ol  palladium. 

Palladium  forms  with  gold  a  grey  alloy,  harder  than 
gold,  less  ductile  than  platina,  and  of  a  coarse-grained 
fracture. 

With  an  equal  weight  of  platina,  it  resembles  platina 
in  colour  and  hardness;  but  it  is  not  so  malleable,  and 
melts  at  a  heat  a  little  higher  than  is  requisite  to  fuse 
the  palladium.  The  specific  gravity  of  this  alloy  is 
15.141. 

With  an  equal  weight  of  silver,  the  alloy  is  harder 
than  silver,  but  softer  than  wrought-iron,  and  its  polished 
surface  resembles  platina,  except  that  it  is  rather  whiter ; 
specific  gravity  1.29. 

Equal  parts  of  palladium  and  copper,  are  a  little  more 
yellow,  break  more  readily,  assume  somewhat  of  a  lead¬ 
en  hue  when  filed,  and  are  harder  than  wrought  iron. 
Specific  gravity  10.392. 

Lead  increases  the  fusibility  of  palladium,  and  forms 
with  it  an  alloy  of  a  grey  colour,  fine-grained  fracture, 
harder  than  any  of  the  preceding  alloys,  but  very  brittle 

With  tin,  bismuth,  iron,  and  arsenic,  palladium  forms 
brittle  alloys :  that  with  bismuth  is  very  hard. 


106 


CHEMISTRY. 


LEAD. 

The  colour  of  lead  is  a  bluish  white ;  its  speciuc 
gravity  is  11.352  ;  its  hardness  is  5  ;  it  is  the  softest,  the 
least  elastic  and  sonorous,  of  all  metals  used  in  the  arts. 
It  melts  before  ignition.  It  has  scarcely  any  taste,  but 
friction  causes  it  to  emit  a  peculiar  smell.  It  stains  paper 
and  the  fingers  of  a  bluish  black. 

Lead  is  very  malleable,  and  therefore  easily  reduced 
to  thin  plates  by  the  hammer ;  but  hammering  neither 
increases  its  specific  gravity  or  hardness.  Its  ductility 
is  not  great ;  a  wire  one-tenth  of  an  inch  in  diameter, 

will  support  only  29^  pounds. 

It  is  not  certainly  known  that  lead  has  ever  been 
found  in  the  metallic  state;  the  only  lead  ore  that  is  ex¬ 
tensively  found  and  worked,  is  a  sulphuret  of  lead  ,  it  is 
called  galena,  and  is  generally  found  in  veins,  both  in 
siliceous  and  calcareous  rocks.  Lead  ore  frequently  con¬ 
tains  silver,  and  often  antimony  and  bismuth. 

To  obtain  lead  from  galena,  the  galena  is  pulverized, 
and  separated  by  washing  from  earthy  admixtures;  it  is 
then  roasted  in  a  reverberating  furnace,  and  afterwards 
melted  in  contact  with  charcoal.  When  the  lead  con¬ 
tains  a  quantity  of  silver  worth  extracting,  it  is  fused  ii. 
a  strong  fire,  and  the  wind  from  a  pair  of  bellows  being 
directed  over  its  surface,  the  whole  of  it  is  in  succession 
converted  into  a  yellow  scaly  substance  called  litharge, 
which  being  driven  oiF  as  it  forms,  the  silver  is  left  at  the 
bottom  of  the  crucible.  The  litharge  is  a  sub-carbonate 
of  lead,  and  by  fusing  it  with  charcoal  the  lead  is  revived. 

When  lead  is  fused  in  an  open  vessel,  its  surface 
quickly  loses  its  lustre,  and  a  scum  appears,  which  is 
soon  converted  into  a  darkish  grey  powder.  In  the  heat 
usually  employed  to  melt  lead,  this  grey  powder  or  ox¬ 
ide  sustains  no  further  alteration  ;  but,  it  spread  upon  a 
suitable  surface,  and  exposed  to  a  low  red  heat,  it  be¬ 
comes  successively  whitish,  yellow,  and  lastly,  of  a  bright 
orange  red.  The  yellow  oxide  is  called  by  painters 
masticot ;  the  red  they  call  minium,  or  merely  red  lead 


LEAD. 


107 

If  the  heat  be  urged  much  further,  red  lead  is  converted 
into  litharge,  which  is  a  semi-vitreous  substance ;  that,  by 
a  little  further  heat,  becomes  a  complete  yellow  glass, 
ot  so  fusible  a  nature,  as  to  penetrate  and  destroy  the 
best  crucibles.  This  glass  enters  into  the  composition  of 
flint-glass.  It  promotes  ,its  fusibility,  renders  it  heavier 
than  other  glass,  better  capable  of  bearing  sudden 
changes, of  temperature,  and  from  its  greater  softness, 
more  suitable  for  cutting  and  polishing. 

When  lead  is  exposed  to  the  atmosphere,  the  bright¬ 
ness  of  its  surface  gradually  diminishes,  till  it  is  nearly 
of  the  same  colour  as  the  grey  oxide  produced  by  heat. 
This  oxide  forms  an  even  but  a  very  superficial  cover¬ 
ing,  and  it  defends  the  metal  from  any  further  change. 

Most  of  the  acids  have  an  action  on  lead ;  but  for  this 
purpose  the  sulphuric  acid  must  be  concentrated  and 
boiling.  Sulphurous  acid  gas  escapes  during  the  solution, 
and  the  acid  is  decomposed.  By  distilling  the  solution 
to  dryness,  a  sulphate  of  lead  is  obtained  :  it  is  of  a  white 
colour,  and  affords  crystals.  This  sulphate  is  caustic,  and 
may  be  decomposed  by  lime  and  the  alkalies. 

The  nitric  acid  has  a  strong  action  upon  lead,  which, 
if  concentrated,  it  converts  into  a  white  oxide  ;  but  if  di¬ 
luted,  it  dissolves  the  metal,  and  forms  nitrate  of  lead, 
which  is  crystallizable.  Lime,  and  the  alkalies  decom¬ 
pose  the  nitric  solution.  Nitrate  of  lead  decrepitates  in 
the  fire,  and  is  fused  with  a  yellowish  flame  upon  ignited 
coals.  Sulphuric  acid  will  take  lead  from  the  nitric 
acid,  falling  down  upon  being  added  to  it,  combined  with 
the  metallic  oxide.  The  muriatic  acid  carries  down 
the  lead  in  the  same  manner,  and  forms  a  muriate  of 
lead  formerly  called  plumbum  corneum.  This  is  soluble 
in  water. 

If  the  nitric  acid,  of  the  specific  gravity  of  1.200,  be 
poured  upon  the  red  oxide  of  lead,  185  parts  of  the 
oxide  are  dissolved  ;  but  15  parts  remain  in  the  state  of  a 
deep  brown  powder.  This  powder  is  the  brown  oxide 
of  lead :  it  contains  21  per  cent,  of  oxygen. 

The  muriatic  acid,  assisted  by  heat,  dissolves  a  part 


CHEMISTRY. 


108 

of  the  lead  put  into  it,  and  oxidizes  another  part.  'I  he 
stion^  affinity  of  the  oxides  of  lead  for  muriatic  acid, 
causes  them  to  decompose  almost  every  substance  in 
which  this  acid  is  found,  by  combining  with  it.  1  bus, 
when  volatile  alkali  is  obtained  by  distilling  muriate  of 
ammonia  with  the  oxides  of  lead,  the  residuum  is  muriate 
of  lead :  the  oxides  of  lead  will  even  disengage  the  vola¬ 
tile  alkali  in  the  cold.  Muriate  of  soda  is  decomposed 
if  fused  with  litharge ;  the  lead  uniting  as  in  the  last- 
mentioned  case  with  the  muriatic  acid,  and  forming  a 
yellow  compound  for  the  manufacture  and  use  of  which, 
as  a  pigment, ja.  patent  has  been  obtained. 

The  acetous  acid  dissolves  lead  and  its  oxides.  1  he 
white  oxide  of  lead,  known  in  commerce  by  the  name 
of  white  lead ,  is  prepared  by  its  means.  The  lead  is 
cast  in  thin  plates,  which  are  rolled  up  in  the  manner  of 
a  watch-spring,  with  a  narrow  space  between  each  coil. 
They  are  then  placed  vertically  in  earthen  pots,  which 
contain  a  quantity  of  good  vinegar,  but  their  lower  edge 
is  prevented  from  coming  in  contact  with  the  vinegar  by 
suitable  projections  from  the  sides  of  the  pots.  The  pots 
are  then  covered,  and  bedded  in  tan  in  a  close  apart¬ 
ment.  The  vapour  of  the  acid  slowly  converts  the  sur¬ 
face  of  the  lead  into  a  white  oxide,  which  is  separated 
by  shaking  or  uncoiling  the  plates.  1  he  plates  are  then 
re-submitted  to  the  same  process,  until  nearly  consumed, 
when  they  are  melted  up,  and  cast  over  again.  1  he 
white  oxide  thus  obtained,  is  prepared  for  sale  by  wash¬ 
ing  it  in  water,  and  drying  it  in  the  shade:  it  is  then 
called  indiscriminately  white  lead  or  ceruse,  though  some 
onlv  give  the  name  of  ceruse  to  its  mixture  with  chalk. 
If  white  lead  be  dissolved  in  acetous  acid,  it  atlbrds  a 
crystallizable  salt  or  acetate,  which,  from  its  sweet  taste, 
is  called  sugar  of  lead.  From  its  effiect  in  diminishing 
aciditv,  sour  wines  have  been  sweetened  by  the  addition 
of  white,  lead,  a  practice  which  merits  the  severest  repro¬ 
bation,  as  the  oxides  of  lead  are  the  mast  destructive 
poisons,  in  whatever  way  received  into  the  animal  sys¬ 
tem,  whether  in  solution,  by  breathing  the  dust  which 


SILVER. 


109 


arises  from  them,  or  by  working  among  them  with  the 

hands.  . 

The  oxides  of  lead  dissolve  in  oils,  of  which  they  cor¬ 
rect  the  rancidity,  and,  therefore,  they  have  sometimes 
been  added  to  the  finer  oils  with  fraudulent  intentions. 
Linseed  and  other  drying  oils  are  rendered  still  more 
strongly  desiccative  by  boiling  upon  oxide  of  had. 

Pure  alkaline  solutions  corrode  lead,  and  dissolve  a 

small  quantity  of  it.  , 

Phosphoric  acid,  if  heated  with  charcoal  and  lead, 
becomes  converted  into  phosphorus,  which  combines 
with  the  metal.  This  phosphuret  differs  not  much  from 
common  lead:  it  is  malleable,  and  easily  cut  with  a 
knife  ;  but  it  sooner  loses  its  brilliancy  than  common  *ea(j.’ 
and  by  fusion  the  phosphorus  is  burnt,  and  the  lead  lett 

pure. 

SILVER. 


Silver  is  the  whitest  of  all  metals,  and  next  to  gold, 
it  is  the  most  malleable  and  ductile.  Under  the  ham¬ 
mer,  the  continuity  of  its  parts  is  not  destroyed,  until  its 
leaves  are  not  more  than  the  T^oloTir  an  inch  t  nc  ' ; 
and  it  may  be  drawn  into  wire  finer  than  a  human  hair. 

The  specific  gravity  of  silver  is  10.474  ;  its  hardness 
is  6.5.  It  continues  melted  at  28°  of  Wedge  wood;  but 
a  greater  heat  is  required  to  bring  it  into  fusion.  Its 
tenacity  is  such,  that  a  wire  of  one-tenth  of  an  inch  in 
diameter,  will  sustain  a  weight  of  270  pounds,  without 
breaking. 

Silver  has  neither  smell  nor  taste.  It  is  not  altered 
bv  the  contact  of  air,  unless  containing  sulphurous  va¬ 
pours  ;  but  it  may  be  volatilized  by  an  intense  heat,  and 
Lavoisier  oxidized  it  by  the  blow-pipe  and  oxygen  gas. 
By  exposing  silver  twenty  times  successively  to  the  heat 
ff  a  porcelain  furnace,  Macquer  converted  it  into  glass, 

>f  an  olive-green  colour.  . 

Silver  is  found,  in  greater  or  less  abundance,  in  almost 
ill  countries  which  contain  mines;  but  the  greatest  quan¬ 
tities  of  it  are  obtained  from  the  mines  of  Peru  and 


10 


110 


CHEMISTRY. 


Mexico.  The  celebrated  mine  of  Potosi,  which  is  situ¬ 
ated  near  the  source  of  the  Rio  de  la  Plata,  is  one  of  the 
most  considerable  mountains  of  Peru;  and  this  mountain 
is  described  by  travellers  as  filled  with  veins  of  silver 
from  the  top  to  the  bottom. 

Silver  is  often  found  native  in  ramifications  consisting 
of  octahedrons  inserted  in  each  other,  also  in  small  inter- 
winded  threads,  and  in  masses  ;  but  it  is  most  commonly 
ound  in  combination  with  sulphur. 

Silver  forms  alloys  with  most  of  the  metals.  Copper 
is  the  metal  with  which  it  is  alloyed  for  the  purpose  of 
coinage.  The  British  coinage  contains  1 1  ounces  2 
pennyweights  of  fine  silver  in  the  pound  troy.  Copper 
stiffens  silver,  and  increases  its  elasticity,  but  renders  it 
less  ductile. 

The  alloy  of  silver  and  zinc  is  granulated  on  its  sur¬ 
face,  and  very  brittle.  Tin,  also,  in  the  smallest  quanti¬ 
ties,  deprives  silver  of  its  malleability.  Alloyed  with  lead, 
silver  ceases  to  be  sonorous  and  elastic. 

Fine  filings  of  silver,  triturated  with  mercury  in  a 
warm  mortar,  form  an  amalgam,  which  by  fusion  and 
slow  cooling,  affords  tetrahedral  prismatic  crystals,  ter¬ 
minated  by  pyramids  of  the  same  form.  The  mercury 
cannot  be  separated  from  the  silver,  except  by  a  much 
stronger  heat  than  would  be  required  to  volatilize  it 
alone. 

The  sulphuric  acid  dissolves  silver,  if  concentrated  anc 
boiling,  and  the  metal  in  a  state  of  minute  division.  The 
action  of  the  muriatic  acid  upon  silver  is  very  trifling, 
unless  oxygenized. 

The  nitric  acid,  a  little  diluted,  has  a  powerful  action 
upon  silver,  of  which  it  will  dissolve  half  its  weight.  The 
solution  is  at  first  blue;  this  colour  disappears  when  the 
silver  is  pure;  but  becomes  green  if  it  contains  copper. 
If  the  silver  contains  gold,  this  metal  separates  in  black¬ 
ish  coloured  flocks.  The  solution  is  extremely  corrosive, 
and  destructive  to  animal  substances.  When  the  acid  is 
fully  saturated,  it  deposits  crystals  as  it  cools,  and  also  by 
evaporation.  Those  crystals  are  called  lunar  nitre,  or 


SILVER. 


Ill 


nitrate  of  silver.  By  fusion,  for  which  a  gentle  heat  is 
sufficient,  their  water  of  crystallization  is  driven  off;  and 
also  a  part  of  the  acid,  by  which  they  become  a  subni¬ 
trate  ;  this  forms  the  lapis  infernalis,  or  lunar  caustic 
of  the  surgeons ;  it  is  of  a  black  colour,  and  usually  cast 
in  the  form  of  small  sticks.  A  heat  a  little  above  what 
is  necessary  for  fusing  the  nitrate,  separates  the  whole 
of  the.  acid,  and  the  silver  is  revived.  Lunar  caustic 
should  be  made  of  silver  entirely  free  from  copper,  as 
the  copper  is  poisonous  to  wounds. 

The  causticity  of  this  and  all  other  mineral  solutions, 
is  attributed  to  the  strong  propensity  of  the  metal  to 
assume  the  metallic  state;  in  consequence  of  which,  it 
readily  parts  with  its  oxygen  to  substances  it  is  in  con¬ 
tact  with  ;  and,  therefore,  such  substances  as  are  capa¬ 
ble  of  receiving  the  oxygen,  virtually  undergo  a  combus¬ 
tion. 

A  solution  of  nitrate  of  silver  in  water,  is  perfectly 
free  from  colour  ;  but  it  stains  the  skin,  and  all  animal 
and  vegetable  substances,  an  indelible  black.  It  is 
employed,  in  a  weak  state,  to  dye  the  human  hair,  and 
when  mixed  with  a  little  gum-water,  forms  a  permanent 
ink  for  marking  linen.  It  is  employed  for  staining  mar¬ 
ble  and  other  stones.  • 

Nitrate  of  silver  is  a  most  powerful  antiseptic ;  a 
12,000th  part  of  it  dissolved  in  water  will  render  the 
water  incapable  of  putrefaction,  and  it  may  be  separated 
at  any  time  by  adding  some  common  salt. 

Silver  is  precipitated  from  its  solution  in  nitric  acid  by 
muriatic  acid,  in  the  torm  of  a  white  curd,  which,  when 
fused,  forms  a  semi-transparent,  and  rather  flexible  mass, 
resembling  horn ;  it  was  therefore  anciently  called  luna 
cornea  or  horn  silver,  and  is  supposed  to  have  given  rise 
to  some  of  the  accounts  we  have  of  flexible  glass.  It  is 
a  muriate  of  silver,  soon  blackens  in  the  air,  and  is 
scarcely  soluble  in  water. 

The  muriatic  acid  does  not  dissolve  silver,  but  has  a 
strong  affinity  for  its  oxide,  and  as  the  muriate  of  silver 
is  not  very  soluble  in  water,  the  nitrate  of  silver  is  em- 


CHEMISTRY. 


112 

ployed  as  a  re-agent,  to  discover  the  presence  of  muriatic 
acid  in  any  liquid:  for  if  it  contains  that  acid,  muriate  o( 
silver  will  fall  down  in  a  white  cloud,  on  droppjng  nitrate 
of  silver  into  it. 

The  nitric  acid  sold  in  the  stores  generally  contains 
muriatic  or  sulphuric  acid,  or  both  ;  hence  the  nitrate  of 
silver  is  employed  to  free  the  nitric  acid  from  the  two 
latter  acids.  For  this  purpose,  nitrate  of  silver  is  poured 
into  it  by  degrees,  until  no  more  precipitate  is  produced 
after  which  it  is  rendered  clear  by  filtering.  Nitric  acid 
thus  purified,  is  called  by  artists  precipitated  aquafortis ; 
but  it  still  contains  some  silver,  from  which  it  cannot  be 
freed  except  by  distillation. 

When  mercury  is  added  to  the  nitric  solution  of  silver , 
a  precipitation  of  the  silver  is  formed,  which,  from  its 
resemblance  to  vegetation,  is  called  arbor  Diance,  or  tree 
of  Diana. 

A  few  drops  of  nitrate  of  silver,  laid  upon  glass,  with 
a  copper-wire  in  it,  afford  another  beautiful  precipitation 
of  the  silver,  in  the  form  of  a  plant. 

Silver  supplies  a  fulminating  powder,  incomparably 
more  dangerous  than  any  other:  the  nitric  solution  of 
fine  silver  is  precipitated  by  lime-water;  the  water  is 
decanted  ;  and  the  oxide  is  exposed  for  two  or  three  (lavs 
to  light  and  air.  This  dried  oxide  being  mixed  with 
ammonia,  or  volatile  alkali,  assumes  the  form  of  a  black 
powder;  decant  the  fluid,  and  leave  the  powder  to  dry 
in  the  open  air.  This  powder  is  the  fulminating  silver, 
which,  after  having  been  once  made,  can  no  longer  be 
touched ;  it  must  therefore  be  left  in  the  vessel  in  which 
the  evaporation  was  performed.  It  should  never  be 
made  but  in  minute  quantities,  and  not  more  than  the 
fulmination  of  a  grain  should  be  attempted  at  once.  „ 

The  avidity  with  which  sulphur  enters  into  combina¬ 
tion  with  silver,  is  instanced  by  Proust,  in  its  tarnishing 
when  exposed  in  churches,  theatres,  and  other  places, 
much  frequented  by  men.  This  tarnish  soon  becomes 
a  real  crust,  which,  on  examination,  is  found  to  be  a  sul- 
phuret  of  silver.  It  can  only  be  detached  by  bending 


NICKEL. 


113 


the  silver,  or  breaking  the  silver  to  pieces,  and  its  colour 
is  a  deep  violet,  like  the  sulphuret  of  silver  formed  by 
fusion.  Proust  is  of  opinion  that  sulphur  is  constantly 
formed  and  exhaled  by  living  bodies. 

The  sulphuret  of  silver  is  brittle,  and  more  fusible  than 
silver.  By  a  sufficient  heat  alone,  the  sulphur  is  vola¬ 
tilized,  and  the  metal  entirely  recovered. 

NICKEL. 

Nickel  is  a  metal  of  greyish  white  colour,  between 
that  of  tin  and  silver ;  but  when  not  pure,  it  is  reddish, 
which  is  the  colour  of  its  ore.  It  is  both  ductile  and 
malleable,  when  cold  and  red-hot.  Its  specific  gravity 
is  9.000,  and  its  hardness  is  8.  It  is  not  fused  at  a  less 
heat  than  150°  of  Wedgwood. 

The  ore  of  the  nickel  has  been  long  known  to  the 
miners  of  Germany,  where,  from  its  resemblance  to  that 
of  copper,  it  is  called  kupper-nickeJ,  or  false  copper. 
Bergman  was  the  first  who  discovered  that  it  contained 
a  peculiar  metal. 

Nickel  is  strongly  attracted  by  the  magnet,  and  at¬ 
tracts  iron.  On  this  account,  it  was  supposed  to  contain 
iron ;  but  Chenevix  and  Pvichter  discovered  that  a  very 
small  portion  of  arsenic  prevents  nickel  from  being  affect¬ 
ed  by  the  magnet.  When  it  is  not  attractable,  therefore, 
the  presence  of  arsenic  may  be  suspected.  P o  separate 
arsenic  from  nickel,  Chenevix  boiled  the  compound  in 
nitric  acid,  till  the  nickel  was  converted  into  an  arse- 
niate,  decomposed  this  by  a  nitrate  of  lead,  and  evapo¬ 
rated  the  liquor  not  quite  to  dryness.  He  then  poured 
in  alcohol,  which  dissolved  only  the  nitrate  of  nickel. 
The  alcohol  being  decanted  and  evaporated,  he  re-dis¬ 
solved  the  nitrate  in  water,  and  precipitated  it  by  potass. 
The  precipitate,  well  washed  and  dried,  he  reduced  in 
a  Ilessian  crucible,  lined  with  lamp-black,  and  found  it 
to  be  perfectly  magnetic;  but  this  property  was  de¬ 
stroyed  again  by  alloying  the  metal  with  a  small  poruon 
of  arsenic.  TT 

10  *  -  11 


CHEMISTRY. 


1)4 

The  kupfur-nickel  of  the  Germans,  is  the  sulphuret  of 
nickel,  and  besides  generally  contains  arsenic,  iron,  and 
cohalt.  This  ore  is  roasted,  to  drive  off  the  sulphur  and 
arsenic,  then  mixed  with  two  parts  of  black  flux,  put 
into  a  crucible,  covered  with  muriate  of  soda,  and  heated 
in  a  forge  furnace.  The  metal  thus  obtained,  which  is 
still  very  impure,  may  be  dissolved  in  diluted  nitric  acid, 
and  then  evaporated"  to  dryness;  after  this  process  has 
been  repeated  three  or  four  times,  the  residuum  must  be 
dissolved  in  a  solution  of  ammonia  perfectly  free  from 
carbonic  acid.  Being  again  evaporated  to  dryness,  it  is 
now  to  be  well  mixed  with  two  or  three  parts  of  black 
flux,  and  exposed  to  a'violent  heat  in  a  crucible,  for  half 
an  hour  or  more. 

Richter  says,  that  pure  nickel  is  not  liable  to  be 
altered  by  the  atmosphere ;  hence  it  is  better  adapted 
than  steel  for  compass  needles. 

By  exposing  nickel  to  heat  with  nitre,  an  oxide  of  it  is 
obtained  of  a  greenish  colour,  if  the  metal  be  impure ; 
but  if  otherwise,  brown ;  this  oxide  contains  33  parts  in 
the  100  of  oxygen. 

The  French  manufacturers  of  porcelain  are  said  to 
use  the  oxide  of  nickel  in  producing  a  delicate  grass 
green.  A  hyacinthine  coloui  may  be  given  to  flint-glass 
by  the  same  oxide. 

Proust  observes,  that  a  certain  proportion  of  nickel 
increases  the  whiteness  of  iron,  diminishes  its  disposition 
to  rust,  and  adds  to  its  ductility.  In  Birmingham,  it  is 
occasionally  combined  with  iron  and  brass.  The  Chinese, 
also,  employ  it  in  conjunction  with  copper  and  zinc  for 
children’s  toys.  It  is  the  difficulty  of  working  this  metal, 
rather  than  its  scarcity,  that  renders  it  so  little  known. 

Equal  parts  of  copper  and  nickel  form  a  red  ductile 

alloy.  The  alloys  of  it  with  tin  and  zinc  are  brittle. 

Equal  parts  of  silver  and  nickel  form  a  white  ductile 

alloy.  It  does  not  amalgamate  with  mercury.  Nickel 
is  soluble  with  most  of  the  acids,  but  the  action  ot  the 
sulphuric  and  muriatic  is  not  considerable.  The  nitric 
and  nitromuriatic.  acids  are  its  proper  solvents.  The 


COPPER. 


115 


citric  solution  is  of  a  tine  green  grass  colour,  and  by 
evaporation  aflords  green  crystals  in  rhomboidal  cubes. 

Cronsted  found  that  nickel  combines  with  sulphur  by 
fusion,  and  that  the  result  is  hard  and  yellow,  with  small 
brilliant  facets;  but  the  nickel  which  he  employed  was 
impure. 

lXickel  combines  readily  with  phosphorus,  either  by 
fusion  along  with  phosphoric'  glass,  or  by  dropping  phos¬ 
phorus  upon  it  while  it  is  red-hot.  1  he  phosphnret  of 
nickel  is  of  a  white  colour,  and  when  broken,  exhibits 
the  appearance  of  very  slender  prisms  united  together. 

It  is  remarkable  that  all  those  bodies  called  meteoric 
stones,  which  have  at  different  times  fallen  from  the 
atmosphere,  contain  nickel. 

COPPER. 

Copper  is  of  a  pale  red  colour,  inclining  to  yellow.  It 
has  a  styptic  and  unpleasant  taste,  and  emits,  by  friction, 
a  disagreeable  smell.  Its  hardness  is  8 ;  its  specific  gra¬ 
vity  is  7.788.  In  point  of  malleability,  it  is  not  much 
inferior  to  silver.  It  is  sometimes  found  native. 

If  copper  be  made  red-hot,  in  contact  with  air,  its  sur¬ 
face  rapidly  oxidizes,  and  the  oxide  may  be  separated 
by  the  hammer,  or  by  plunging  the  oxide  into  water. 
By  the  repetition  of  the  process,  another  scale  will  be 
formed  ;  and  this  may  be  continued,  till  the  whole  of  the 
metal  disappears.  These  scales  are  a  brown  oxide  of 
copper,  which  contains  64  parts  of  copper,  and  16  of 
oxygen.  This  oxide  may  be  converted  into  a  brown 
glass,  by  a  strong  heat. 

When  exposed  to  the  air,  copper  becomes  covered 
with  a  green  cfust,  which  is  the  green  oxide  of  copper. 
This  change  takes  place  only  at  the  surface,  the  oxide 
itself  forming  a  defence  from  further  change. 

Filings  of  copper,  thrown  upon  burning  coals,  burn 
with  a  greenish  flame,  and  when  the  metal  is  kept  in  a 
greater  heat  than  what  is  necessary  for  its  fusion,  it  burns 
with  a  flame  of  the  same  colour. 


CHEMISTRY. 


116 

Most  of  the  alloys  of  copper  have  been  already  no* 
ticed.  This  metal,  with  iron,  forms  the  alderado ,  or 
Keir’s  patent  metal  for  window- frames,  designed  to  com¬ 
bine  elegance  with  strength.  Copper  unites  very  readily 
with  antimony,  and  forms  an  alloy,  distinguished  by  a 
beautiful  violet  colour. 

Concentrated  sulphuric  acid  dissolves  copper  by  the 
assistance  of  heat,  and  the  crystals  of  the  solution,  after 
adding  water  to  it,  form  a  sulphate  of  copper ,  generally 
called"  blue  vitriol.  If  to  this  sulphate  of  copper  be  added 
a  solution  of  arseniate  of  potass,  a  beautiful  green  pre¬ 
cipitate  is  formed,  called  Scheele's  green,  or  mineral- 
green.  Magnesia,  lime,  and  the  fixed  alkalies,  precipi¬ 
tate  copper  from  its  solution  in  sulphuric  acid,  in  the  form 
of  an  oxide. 

The  muriatic  acid  does  not  dissolve  copper,  unless  con¬ 
centrated  and  in  a  state  of  ebullition  ;  the  solution  is 
green  ;  the  muriatic  is  caustic  and  astringent,  fuses  by  a 
gentle  heat,  and  congeals  into  a  mass. 

The  nitric  acid  attacks  copper  with  effervescence.  A 
large  quantity  of  nitrous  gas  is  disengaged.  The  acid 
first  oxidizes  the  metal,  and  then  dissolves  the  oxide. 
The  solution  has  a  blue  colour,  much  deeper  than  that 
by  sulphuric  acid,  and  affords  crystals  by  slow  evapora¬ 
tion.  Lime  precipitates  the  metal  of  a  pale  blue. ,  fixed 
alkalies,  of  a  bluish  white.  Volatile  alkali  throws  down 
bluish  flocks,  which  are  quickly  re-dissolved,  and  produce 
a  lively  blue  colour  in  the  fluid. 

The  acetous  acid  highly  concentrated,  dissolves  copper; 
but  when  not  concentrated,  it  only  corrodes  the  metal, 
and  forms  the  oxide  called  verdigris.  This  oxide,  dissolved 
in  vinegar,  forms  a  salt  called  by  the  chemists  crystallized 
acetate  of  copper,  and  in  commerce  distilled  verdigris. 

Copper  is  precipitated  from  its  solution  by  iron.  The 
iron  is  simply  immersed  in  the  solution  ;  the  acid  seizes 
upon  it,  and  abandons  the  copper.  The  copper  obtained 
by  this  means  is  called  copper  of  cementation.  Sulphate 
of  copper  is  frequently  found  in  streams  of  water  from 
copper  mines;  the  quantity  of  salt  which  they  contain  is 


COPPER. 


117 


not  sufficient  to  reimburse  the  expense  of  evaporating 
the  water  to  obtain  blue  vitriol ;  but  by  throwing  waste 
pieces  of  iron  into  them,  the  salt  is  decomposed,  and  the 
copper  is  precipitated  in  a  metallic  form,  because  the 
sulphuric  acid  has  a  greater  attraction  for  iron  than 
copper.  It  appears  in  effect  as  if  the  iron  was  changed 
into  copper,  and  to  the  superficial  observer  favours  the 
idea  that  metals  are  transmutable.  The  streams  of 
mines  thus  containing  sulphate  of  copper  are  often  as 
valuable  as  the  ore  itself. 

All  the  salts  of  copper  are  poisonous;  and  copper 
vessels  should  therefore  never  be  used  to  contain  any 
vehicle  capable  of  holding  the  metal  in  solution.  In 
Sweden,  the  use  of  copper  vessels  for  culinary  purposes, 
»ias  been  prohibited  by  law,  and  a  statue  of  the  metal 
dedicated  to  the  man,  at  whose  solicitation  it  was  ob¬ 
tained.  * 

Sulphur  combines  with  copper  at  a  strong  heat. 
Sulphuret  of  copper  is  brittle,  softer  than  copper,  of  a 
black  colour  externally,  and  within  of  a  leaden  grey. 

A  phosphuret  of  copper  may  be  formed  by  casting 
phosphorus  upon  red-hot  copper.  It  has  the  hardness  of 
steel,  but  is  too  brittle  and  refractory  to  be  useful. 

Prussic  acid  unites  with  the  oxide  of  copper,  and  forms 
a  brown  pigment,  superior,  both  in  oil  and  water,  accord¬ 
ing  to  the  experience  of  Hatchet,  to  any  other  in  use. 
It  has  a  purple  tinge,  so  as  to  form  various  shades  of 
bloom  or  lilac  when  mixed  with  white,  and  which  are 
not  liable  to  fade  as  those  made  with  lake.  The  best 
mode  of  preparing  the  prussiate  of  copper,  is  to  dissolve 
the  green  muriate  in  ten  parts  of  distilled  water,  and 
precipitate  with  prussiate  of  lime. 

Fixed  alkalies  have  some  action  on  copper,  with  which 
they  form  a  light  blue  solution ;  the  effect  is  greatest  in 
the  cold. 

Ammonia  dissolves  copper  with  much  greater  rapid¬ 
ity  than  fixed  alkalies,  whether  it  be  in  the  state  of 
metal  or  an  oxide,  and  forms  a  beautiful  blue  solution. 
This  solution,  when  recently  made,  is  colourless  if  the 


CHEMISTRY. 


118 

vessel  be  closed,  but  when  the  vessel  is  opened,  the  colour 
returns,  gradually  extending  from  the  surface  downwards 

Oils  appear  to  have  no  action  on  copper,  until  they 
become  rancid,  in  which  case  their  disengaged  acid  cor- 
rodes  the  copper,  and  the  oil  assumes  a  bluish  green 
colour. 

'  IRON. 

Ikon  is  of  a  bluish  white  colour,  highly  elastic,  sonor* 
ous,  has  a  styptic  taste,  emits  a  peculiar  odour  when 
rubbed,  and  strikes  fire  with  flint.  In  tenacity  it  exceeds 
all  metals;  wire  of  it,  only  one-tenth  of  an  inch  in  dia¬ 
meter,  sustaining  a  weight  of  450  pounds  without  break¬ 
ing.  Its  specific  gravity  is  7.788. 

Iron  is  less  malleable  than  gold,  silver,  or  copper ;  it 
is  of  all  the  metals  in  common  use  the  most  difficult  of 
fusion,  but  the  nearer  it  approaches  to  fusion,  the  more 
malleable  and  ductile  it  becomes. 

The  hardness  of  iron,  its  great  tenacity,  the  facility 
with  which  it  may  at  a  white  heat  be  fashioned  and 
welded,  are  the  properties  which  render  it  so  valuable. 

Iron  is  attracted  by  the  magnet  or  loadstone,  and  is 
itself  capable  of  being  rendered  magnetic ;  but  this  pro¬ 
perty,  .after  having  been  communicated  to  it,  is  retained 
only  a  short  time,  unless  it  be  in  the  state  of  hard  steel. 

If  suddenly  plunged  into  cold  water,  while  red-hot,  it 
is  rendered  rather  more  rigid  than  before,  but  gradually 
cooling,  renders  it  soft. 

Iron  is  sometimes  found  native.  In  the  museum  of  the 
academy  of  science  at  Petersburg!),  is  a  mass  of  native 
iron,  1200  tons  in  weight. 

Cast-iron  is  that  which  results  from  the  fusion  of  the 
iron  ore  with  charcoal:  its  peculiar  properties  are  owing 
to  its  containing  carbon,  and  other  foreign  matters. 

Steel  is  iron  deprived  of  all  impurities  except  a  small 
portion  of  carbon :  it  is  more  ductile  than  iron,  and  a 
finer  wire  may  be  drawn  from  it  than  any  other  metal. 

Iron,  united  with  about  nine-tenths  of  charcoal,  lorms 
plumbago,  or  hyper-carburet  of  iron. 


in 


IRON. 

Iron  has  a  greater  affinity  for  oxygen  than  oxygen  has 
for  hydrogen ;  it  therefore  decomposes  water  by  combin¬ 
ing  with  its  oxygen  ;  which  is  the  cause  of  its  being  easily 
altered  by  exposure  to  damp  air  or  water. 

The  action  of  air,  assisted  by  heat,  converts  a  thick 
pellicle  of  the  surface  of  iron  into  a  black  oxide,  contain¬ 
ing  25  per  cent,  of  oxygen  ;  and  when  this  is  hammered 
off,  another  is  quickly  formed.  This  black  oxide  is  at¬ 
tracted  in  some  degree  by  the  magnet.  If  it  be  collected, 
and  exposed  to  a  strong  heat  under  a  muffle,  it  becomes 
a  reddish  brown  oxide,  containing  48  per  cent,  of  oxy¬ 
gen.  The  yellow  rust  formed  when  iron  is  long  exposed 
to  damp  air,  is  not  a  simple  oxide,  but  contains  a  portion 
of  carbonic  acid.  Proust  only  admits  two  stages  in  the 
oxidation  of  iron,  viz.  the  green,  and  the  brown,  or  red, 
and  considers  the  other  supposed  oxides  to  be  mixtures 
of  these  in  various  proportions. 

The  green  oxide  may  be  obtained  by  dissolving  iron 
in  sulphuric  acid,  and  then  precipitating  it  by  potass. 
This  oxide  contains  27  parts  of  oxygen,  and  73  of  iron, 
in  the  100.  By  exposure  to  the  air,  it  is  converted  into 
brown  oxide,  which  contains  18  parts  of  oxygen,  as  ob¬ 
served  above. 

Concentrated  sulphuric  acid  scarcely  acts  on  iron,  un¬ 
less  ff  be  boiling ;  but,  if  diluted  with  two  or  three  times 
its  weight  of  water,  it  attacks  the  metal  immediately, 
and  a  strong  effervescence  ensues,  without  any  heat  but 
that  produced  by  the  addition  of  the  water.  It  is  the 
hydrogen  gas  of  the  water  which  escapes,  the  oxygen 
being  employed  in  oxidizing  the  metal ;  which  oxide  the 
acid  dissolves  without  being  decomposed.  If  heat  be  ap¬ 
plied,  more  iron  still  is  dissolved.  This  solution  yields, 
by  evaporation,  sulphate  of  iron.  The  common  greeh 
copperas  of  commerce  is  this  salt  in  a  state  of  impurity. 
It  is  much  more  soluble  in  hot  than  in  cold  water;  and, 
therefore,  a  saturated  solution  of  it  in  hot  water  affords 
crystals  in  cooling,  as  well  as  by  evaporation. 

The  substance  called  martial  pyrites  is  a  sulphuret 
of  iron,  and  it  is  from  the  decomposition  of  it,  that  the 


CHEMISTRY. 


120 

extensive  demand  for  sulphate  ot  iron  is  supplied.  By 
fusion  with  iron,  sulphur  produces  a  compound  of  the 
same  nature  as  pyrites. 

The  sulphuret  of  iron,  as  well  as  iron  itself,  burns 
rapidly,  but  without  noise,  when  triturated  in  a  metallic 
mortar  with  hyper-oxy muriate  of  potass.  This  mixture, 
in  a  heap,  if  struck  with  steel,  detonates  strongly,  and 
gives  out  a  red  flame. 

Sulphate  of  iron  is  decomposed  by  alkalies  and  by 
lime.  Caustic  fixed  alkali  precipitates  the  iron  in  deep 
green  flocks,  which  are  dissolved  by  the  addition  of  more 
alkali,  and  form  a  red  tincture.  The  mild  alkali  does 
not  re-dissolve  the  precipitate  it  throws  down,  which  is 
of  a  greenish-white  colour.  Distillation  separates  the 
acid  from  sulphate  of  iron,  and  leaves  the  brownish-red 
oxide  called  colcothar. 

Astringent  vegetables,  such  as  gall-nuts,  oak,  tea,  &c., 
precipitate  a  fine  black  fecula  from  sulphate  of  iron,  and 
this  precipitate  remains  suspended  a  considerable  time  in 
the  fluid,  by  the  addition  of  gum-arabic,  and  hence  its 
utility  as  a  writing  ink.  The  well-known  pigment  called 
prussian  blue,  is  likewise  a  precipitate  afl'orded  by  sul¬ 
phate  of  iron. 

Sulphur  combines  with  iron  merely  by  the  assistance 
of  water;  thus,  if  flowers  of  sulphur  be  mixed  with  iron 
filings,  and  made  into^a  paste  with  water,  it  soon  becomes 
hot,  swells,  and  emits  the  well-known  smell  of  hydrogen, 
with  watery  vapours.  The  mixture  takes  fire,  if  incon¬ 
siderable  quantity,  even  although  huried  in  the  earth. 
It  is  a  composition,  therefore,  which  may  be  used  to  form 
an  artificial  volcano. 

Concentrated  nitric  acid  is  rapidly  decomposed  by  iron, 
a  portion  of  the  oxide  of  the  acid  oxidizes  the  iron,  which 
oxide  dissolves  as  it  is  formed,  and  the  remainder  of  the 
acid  passes  off  in  nitrous  gas.  The  solution  is  of  a  red¬ 
dish  brown,  and  deposits  the  oxide  of  iron  after  a  certain 
time,  particularly  if  exposed  to  the  air.  Diluted  nitric 
acid  allbrds  a  more  permanent  solution  of  iron,  of  a 
greenish,  or  sometimes  of  a  yellow  colour.  Neither  of 


IRON. 


121 


the  solutions  affords  crystals,  but  both  deposit  the  oxide 
of  iron  by  boiling,  at  the  same  time  that  the  fluid  assumes 
a  gelatinous  appearance.  This  magma,  by  distillation, 
affords  fuming  nitrous  acid,  much  nitrous  gas,  and  some 
nitrogen,  a  red  oxide  being  left  behind. 

Iron  appears  to  be  the  only  metal  of  which  the  solu¬ 
tions,  or  combinations  with  oxygen,  are  not  of  a  noxious 
nature.  The  chalybeate  waters  form  the  best  tonics 
which  medicine  possesses. 

The  muriatic  solution  of  iron,  like  all  other  solutions 
of  the  same  metal,  is  decomposed  by  lime  and  alkalies ; 
but  the  precipitates  arc  less  altered,  and  may  be  easily 
reduced,  especially  such  as  are  produced  by  the  addition 
ol  caustic  alkalies.  Alkaline  sulphurets,  sulphuretted 
hydrogen  gas,  and  astringents,  also  decompose  this  as 
well  as  the  other  solutions  of  iron. 

Water  charged  with  carbonic  acid  dissolves  a  con¬ 
siderable  quantity  of  irou.  Vinegar  appears  to  have 
little  or  no  effect  upon  iron,  unless  assisted  by  the  air. 

If  equal  parts  of  iron  chippings,  and  phosphoric  glass, 
be  melted  together,  a  phosphuret  of  iron  is  obtained, 
which  is  very  brittle,  and  has  a  whitish  fracture.  Iron, 
in  its  crude  state,  frequently  contains  phosphorus,  which 
renders  cast-iron  very  refractory,  and  forms  the  kind 
called  cold-short  iron,  which  is  malleable  when  hot, 
though  brittle  when  cold. 

Gold  unites  easily  with  iron,  and  becomes  by  this 
union  harder  and  less  malleable.  In  the  proportion  of 
six  parts  of  gold  and  one  of  steel,  the  alloy  may  be 
beaten  into  plates  without  cracking.  The  iron  is  only 
partly  separated  by  combustion  in  a  glowing  heat.  Iron 
lias  a  stronger  attraction  than  gold  for  the  oxy-muriatic 
and  nitro-muriatic  acids,  and  precipitates  gold  from  these 
acids  in  its  metallic  state. 

Silver  combines  readily  with  iron.  A  mixture  of 
fourteen  parts  of  silve**,  and  two  and  a  half  iron,  is  more 
elastic  than  silver,  attracts  the  magnet,  and  is  not  decom¬ 
posed  in  a  strong  fire.  A  small  portion  of  iron  does  not 
seem  to  injure  the  colour  or  malleability  of  the  silver 
11 


CHEMISTRY. 


3  22 

Iron  precipitates  silver  from  all  its  solutions  in  acids ;  but 
this  happens  in  the  nitric  only,  when  the  acid  is  not  com 
pletely  saturated,  or  when  nitrous  gas  is  added.  Muriate 
of  silver  is  decomposed  in  the  dry  way  by  its  distillation 
with  iron  tilings. 

Iron  precipitates  mercury  in  its  metallic  state  from  its 
solution  in  acids.  Distil  with  oxymuriate  of  mercury, 
the  muriate  is  decomposed,  and  fluid  mercury  produced. 

Sulphate  of  iron  precipitates  mercury  from  its  solution 
in  nitric  acid,  in  its  metallic  state. 

Lead  is  precipitated  from  its  solutions  in  acids  by  iron. 
Iron  also  precipitates  nickel  from  its  acid  solutions,  and 
in  the  dry  way  takes  from  it  the  sulphur  which  it  con¬ 
tains.  - 

Nickel  has  the  strongest  affinity  for  iron  of  all  the 
metals,  and  is  separated  from  it  with  the  greatest  difficul¬ 
ty.  The  alloy  is  fully  as  malleable,  but  less  fusible  than 
iron  alone.  Nickel  is  precipitated  only  in  a  very  imper¬ 
fect  manner  by  iron  from  its  solutions  in  acids. 

Iron  unites  in  close  vessels  with  arsenic,  which  renders 
it  more  brittle,  diminishes  its  attraction  for  the  magnet, 
and  is  separated  from  it  with  difficulty. 

When  iron  has  been  covered  with  tin,  the  tin  appears 
to  combine  with  it,  and  forms  an  alloy  of  greater  depth 
than  wtmld  readily  be  supposed  ;  even  a  white  heat  is 
insufficient  to  separate  the  tin  entirely,  yet  till  the  whole 
of  it  is  removed,  the  iron  will  not  weld. 

TIN. 

Tin  is  a  white  metal,  intermediate  between  that  of 
lead  and  silver;  it  has  little  elasticity;  its  taste  is  dis¬ 
agreeable,  and  it  has  a  peculiar  smell,  which  increases 
by  friction.  Its  hardness  is  0  ;  its  specific  gravity  7.291 ; 
is  susceptible  of  very  little  increase  by  hammering.  Its 
purity  is  judged  of  by  its  levity,  as  it  cannot  be  alloyed 
with  any  metal  lighter  than  itself. 

The  malleability  of  tin  is  such,  that  it  may  be  extend¬ 
ed  into  leaves  not  more  than  the  2000th  part  of  an  inch 


TIN. 


123 


thick  ;  the  tin-leaf  called  tin-foil,  is,  however,  twice  this 
thickness.  The  tenacity  of  tin  is  but  small ;  a  wire,  one- 
tenth  of  an  inch  in  diameter,  will  support  only  about  49 
pounds  without  breaking.  Its  flexibility  is  considerable; 
it  may  be  bent  several  times  without  breaking,  emitting 
at  the  same  time  a  distinct  crackling  noise. 

All  the  tin  used  in  England  is  supplied  by  the  mines 
of  Cornwall,  which  furnish  3000  tons  annually.  Its  ores 
occur  most  frequently  in  granite,  but  never  in  lime-stone. 
It  is  very  rarely  found  native. 

Chaptal  says,  that  if  tin  be  kept  in  fusion  in  a  lined 
crucible,  and  the  surface  be  covered  with  a  quantity  of 
charcoal  to  prevent  its  calcination,  the  metal  becomes 
whiter,  more  sonorous,  and  harder,  provided  the  fire  be 
kept  up  for  eight  or  ten  hours.  < 

The  brilliant  surface  of  polished  tin  soon  becomes  a 
little  tarnished  by  exposure  to  the  air,  but  the  effect  is 
very  superficial  and  slight. 

Mercury  dissolves  tin  with  great  facility,  and  in  all 
proportions.  To  make  this  combination,  beated  mercury 
is  poured  on  melted  tin ;  the  consistence  of  the  amalgam 
differs  according  to  the  relative  proportions  of  the  two 
metals. 

Nickel  united  to  tin,  forms  a  white  and  brilliant  mass. 
Half  a  part  of  tin,  melted  with  two  parts  of  cobalt,  and 
the  same  quantity  of  muriate  of  soda,  furnished  Beaume 
with  an  alloy  in -small  close  grains  of  a  light  violet 
colour. 

Equal  parts  of  tin  and  bismuth,  form  a  brittle  alloy, 
of  a  medium  colour  between  the  two  metals,  and  the 
fracture  of  which  presents  cubical  facets. 

Zinc  unites  perfectly  with  tin,  and  produces  a  hard 
metal,  of  a  close-grained  fracture.  Its  ductility  increases 
with  t]ie  proportion  of  tin. 

Antimony  and  tin  form  a  white  and  brittle  alloy, 
which  is  distinguished  from  other  alloys  of  tin,  by  Its  pos¬ 
sessing  a  less  specific  gravity  than  either  of  the  two  met¬ 
als  by  which  it  is  formed. 

In  combining  arsenic  with  tin,  precaution  must  be 


124 


CHEMISTRY. 


taken  to  prevent  the  arsenic  from  escaping  by  volatili¬ 
zation.  Three  parts  of  tin  may  be  put  into  a  retort 
with  one-eighth  part  of  arsenic  in  powder;  fit  on  a  re¬ 
ceiver,  anermake  the  retort  red-hot;  very  little  arsenic 
rises,  and  a  metallic  lump  is  found  at  the  bottom,  con¬ 
taining  about  one-fifteenth  part  of  arsenic..  It  crystallizes 
in  large  facets,  is  very  brittle,  and  hard  to  melt. 

If  tin  be  kept  in  fusion,  with  access  of  air,  its  surface 
is  speedily  covered  with  a  greyish  pellicle,  which  is  re¬ 
newed  as  fast  as  it  is  removed.  If  this  grey  oxide  be 
pulverized  and  sifted,  to  separate  the  uncalcined  tin,  and 
calcined  again  for  several  hours  under  a  mu  Hie,  it  be¬ 
comes  the  yellow  oxide  of  tin,  called  among  arhzans 
putty  of  tin,  and  extensively  used  in  polishing  glass,  steel, 

and  other  bard  bodies.  ^  , 

A  white  oxide  of  tin  is  used  in  forming  the  opake  kind 
of  glass  called  enamel.  This  composition  is  made  by 
calcining  100  parts  of  lead  and  30  parts  of  tin  in  a  fur¬ 
nace,  and  then  fluxing  these  oxides  with  100  parts  oi 
sand  and  20  of  potass.  This  enamel  is  white,  anc,  is 

coloured  with  metallic  oxides.  . 

All  the  mineral  acids  dissolve  tin,  and  it  may  be  pre¬ 
cipitated  from  its  solutions  by  potass;  but  an  excess  of 
potass  will  re-dissolve  the  metal.  Nitro-munate  of  gold 
is  a  test  for  tin  in  solution,  with  which  it  forms  a  fine 


purple  precipitate.  .  , 

The  sulphuric  acid  dissolves  tin,  whether  concentrated 
or  diluted  with  water.  Part  of  the  acid  is  decomposed,  - 
and  flics  off  in  the  form  of  sulphurous  acid  gas.  Heat 
accelerates  the  eifect  of  the  ac-id.  Tin  dissolved  in  sub 
phuric  acid  is  very  caustic. 

The  solution  of  tin  in  the  nitric  acid  is  performed 
with  astonishing  rapidity,  and  the  metal  is  precipitated 
(most  instantly  in  the  form  of  a  white  oxide.  11  this 
acid  be  loaded  with  all  the  tin  it  is  capable  ol  calcining, 
and  the  oxide  be  washed  with  a  considerable  quantity 
of  distilled  water,  a  salt  may  be  obtained  by  evapora¬ 
tion,  which  detonates  alone  in  a  crucible  well-heated, 
and  burns  with  a  white  and  thick  flamo,  like  that  of 


TIN. 


125 


phosphorus.  The  nitric  acid  holds  but  a  very  small 
quantity  of  tin  in  solution,  and  when  evaporated  for  the 
purpose  of  obtaining  crystals,  the  dissolved  portion  quickly 
precipitates,  and  the  acid  remains  nearly  in  a  state  of 
purity.  Nitric  acid,  much  diluted,  holds  rather  more 
tin  in  solution,  but  lets  it  fall  by  standing,  or  by  the  ap¬ 
plication  of  heat. 

The  muriatic  acid  dissolves  tin,  whether  cold  or  hot, 
diluted  or  concentrated.  If  fuming  and  assisted  by  a 
gentle  heat,  the  addition  of  the  tin  instantly  causes  it  to 
lose  its  colour  and  property  of  emitting  fumes,  and  a 
slight  effervescence  takes  place.  The  acid  dissolves 
more  than  half  its  weight  of  tin  ;  the  solution  is  yellow¬ 
ish,  of  a  fetid  smell,  and  affords  no  precipitate  of  oxide, 
like  the  sulphuric  and  nitric  acids. 

The  oxymuriatic  acid  dissolves  tin  very  readily,  and 
without  effervescence,  because  the  metal  quickly  absorbs 
the  superabundant  oxygen  from  the  acid,  and  requires 
no  decomposition  of  the  water  to  effect  its  oxidation. 

Nitro-muriatic  acid,  made  with  two  parts  of  nitric  acid 
and  one  of  muriatic  acid,  dissolves  tin  with  effervescence. 

'  It  is  the  solution  of  tin  in  this  acid  which  the  dyers  em¬ 
ploy  to  heighten  the  colour  of  their  scarlet  dyes.  It  is 
prepared  by  adding  small  portions  of  tin  at  a  time  to  the 
common  aquafortis  of  commerce  ;  when  the  appearance 
of  oxide  is  observed  at  the  bottom  of  the  jar,  muriate  of 
soda  is  added,  by  which  its  solution  is  effected.  If  the 
colour  imparted  by  this  solution  is  not  bright,  a  little 
nitrate  of  potass  is  added  to  it. 

The  acetous,  and  most  vegetable  acids,  have  some 
action  upon  tin,  particularly  when  aided  by  a  gentle 
heat ;  but  the  solutions  thus  obtained,  are  not  used  in  the 
arts. 

Tin  decomposes  the  corrosive  muriate  of  mercury.  *It 
is  for  this  purpose  amalgamated  with  a  small  portion  of 
mercury,  and  this  amalgam  being  first  triturated  in  a 
mortar  with  the  corrosive  muriate,  the  mixture  is  then 
distilled  by  a  gentle  heat.  A  colourless  liquor  first  passes 
over,  and  is  followed  by  a  thick  white  vapour,  which 
11  * 


]  20 


CHRMISTRY. 


issues  with  a  kind  of  explosion,  and  covers  the  internal 
surface  of  the  receiver  with  a  very  thin  crust.  The 
Vapour  becomes  condensed  into  a  transparent  liquor, 
which  continually  emits  -a  thick,  white,  and  very  abun¬ 
dant  fume.  It  was  formerly  called  the  fuming  liquor  o' 
Libarius,  and  is  the  combination  of  the  muriatic  acid 
and  tin. 

Tin  has  a  strong  affinity  for  sulphur;  the  sulphuret  of 
tin  may  be  formed  by  fusing  the  two  substances  together 
it  is  brittle,  heavier  than  tin,  and  not  fusible.  It  has  a 
bluish.,  colour,  a  lamellatcd  texture,  and  is  capable  ot 
crystallizing. 

The  white  oxide  of  tin  combines  with  sulphur,  and 
forms  a  compound  called  aurum  musivum ,  or  mosaic 
gold ,  which  is  much  used  for  giving  plaster  of  Paris  the 
resemblance  of  bronze,  and  improving  the  appearance 
of  bronze  itself.  It  is,  also,  occasionally  used  to  increase 
the  effects  of  electrical  machines.  Chaptal  recommends 
for  preparing  it  the  process  of  the  Marquis  de  Bouillon, 
who  directs  an  amalgam  to  be  formed  of  eight  ounces  of 
tin  and  eight  ounces  of  mercury.  In  forming  the  amal¬ 
gam,  a  copper  mortar  is  heated,  and  the  mercury  poured 
into  it,  after  which  the  tin  is  added  in  a  state  of  fusion, 
and  the  mixture  triturated  till  cold.  Six  ounces  of  sul¬ 
phur  and  four  of  muriate  of  ammonia,  arc  then  mixed, 
and  the  whole  put  into  a  matrass,  which  is  to  be  placed 
in  a  sand-bath,  and  heated  to  such  a  degree  ns  to  cause 
a  faint  ignition  in  the  bottom  of  the  matrass.  The  fire 
must  be  kept  up  for  three  hours.  The  aurum  musivum 
obtained  by  this  process  is  usually  excellent;  but  if, 
instead  of  placing  the  matrass  on  the  sand,  it  be  imme¬ 
diately  exposed  upon  the  coals,  and  strongly  and  sudden¬ 
ly  heated,  the  mixture  will  take  tire,  and  a  sublimate 
will  be  formed  in  the  neck  of  the  vessel,  which  consists 
of  (he  most  beautiful  aurum  musivum  that  can  be  pre¬ 
pared. 

The  mercury  and  muriate-  of  ammonia  are  not  in 
strictness  necessary  to  the  production  of  aurum  musivum. 
Bight  ounces  of  tin  dissolved  in  muriatic  acid,  precipi* 


ZINC. 


127 


tated  bv  the  carbonate  of  soda,  and  mixed  with  four 
ounces  of  sulphur,  will  produce  a  line  aurum  musivum, 
but  without  the  properly  of  exciting  electrical  machines. 

A  phosphuret  of  tin  may  be  formed  by  melting  in  a 
crucible  equal  parts  of  tin  and  phosphoric  glass,  or  by 
throwing  small  pieces  of  phosphorus  into  melted  tin.  The 
phosphuret  of  tin  may  be  cut  with  a  knife ;  it  extends 
under  the  hammer,  but  separates  into  laminae.  When 
newly  cut,  it  lias  the  colour  of  silver ;  its  filings  resemble 
those  of  lead,  and  the  phosphorus  takes  fire  when  they 
are  thrown  upon  burning  coals. 


ZINC. 

Zinc  is  a  bluish  white  metal;  its  specific  gravity  is 
7.190;  its  hardness  G.  It  is  distinguished  by  the  singular 
property  of  being  neither  malleable  nor  ductile,  at  com¬ 
mon  temperatures,  but  of  acquiring  both  these  qualities 
at  the  temperature  of  210°  to  «100°.  It  has  neither  taste 
nor  smell.  It  melts  at  the  heat  of  about  /0Q. 

Zinc,  at  a  red  heat,  burns  with  a  bright  white  flame, 
and  throws  out  white  flakes,  called  flowers  of  zinc. 
These  flowers  are  the  white  oxide  of  the  metal ;  they 
are  not  volatile,  but  are  merely  driven  olf  by  the  force 
of  the  combustion.  They  contain  more  oxygen  than  the 
grey  oxide;  which  forms  on  the  surface  of  the  metal 
when  it  is  heated  to  fusion.  The  white  oxide  of  zinc 
may  be  converted  into  a  yellow  glass  by  a  very  violent 

heat.  tit-  i  ii 

Zinc  combines  with  most  of  the  metals.  VV  ith  gold 

it  combines  in  all  proportions.  The  alloy  is  very  hard 

and  white  when  the  metals  are  in  equal  proportions,  and 

takes  a  fine  polish,  without  being  very  liable  to  tarnish. 

One  part  of  zinc  is  said  to  destroy  the  ductility  ot  100 

parts  of  gold.  # 

The  alloy  of  silver  and  zinc  is  also  brittle,  r latina 
unites  with  zinc,  and  forms  a  brittle  fusible  alloy,  toler¬ 
able  hard,  and  of  a  bluish  white  colour,  not  so  clear  as 
that  of  zinc. 


128  CHEMISTRY 

\  ¥ 

One  part  of  zinc,  find  two  and  a  halt  of  mercury 
form  by  fusion  an  amalgam  which  becomes  solid.  It  ia 
used  to  excite  electrical  machines. 

The  well-known  alloy  called  brass,  which  is  formed 
of  zinc  and  copper,  is  usually  formed  by  cementing  cop¬ 
per  in  a  close  crucible  with  calamine,  an  ore  which  con¬ 
tains  zinc  in  the  state  of  an  oxide. 

Tin  and  zinc  combine  readily ;  the  alloy  is  harder  than 
tin:  lead  and  zinc  also  form  alloys  which  are  harder  than 
lead.  Two  parts  of  lead  and  three  of  zinc  form  a  hard 
alloy,  which  bears  hammering  without  extending. 

Iron  and  zinc  have  some  affinity,  as  iron  may  be 
coated  with  zinc  instead  of  tin,  for  culinary  vessels.  The 
solutions  of  zinc  which  may  happen  to  be  obtained,  are 
not  dangerous  like  those  ol  lead. 

If  water  be  thrown  upon  ignited  zinc,  a  part  of  it  it 
decomposed :  the  oxygen  converts  part  ot  the  metal  into 
an  oxide,  and  hydrogen  gas  escapes. 

Sulphuric  acid  dissolves  zinc  without  heat.  A  salt 
may  be  obtained  by  evaporating  the  solution;  this  salt 
which  is  a  sulphate  of  zinc,  is  known  by  the  name  of 
white  vitriol ;  it  has  a  strong  styptic  taste. 

The  nitric  acid  powerfully  attacks  zinc,  and  produces 
much  heat;  and  a  great  part  of  the  acid  is  decomposed; 
but  crystals  may  be  obtained  by  the  slow  evaporation  of 
the  residue.  This  salt,  or  nitrate  of  zinc,  is  deliques¬ 
cent  ;  it  melts  upon  heated  coals,  and  decrepitates,  pro¬ 
ducing  a  slight  reddish  flame.  If  i  oe.exposcd  to  heat 
in  a  crucible,  it  emits  red  vapo  *  assumes  the  consis¬ 
tence  of  a  jelly,  and  preserves  inis  softness  for  a  con¬ 
siderable  time.  The  nitric  solution  of  zinc  is  very 
caustic. 

Muriatic  acid  also  acts  strongly  upon  zinc,  with  the 
disengagement  of  much  hydrogen  gas.  I  he  solution,  bv 
evaporation,  does  not  crystallize,  but  assumes  the  consis¬ 
tence  of  a  jellv,  which  if  distilled,  allows  some  of  the 
acid  to  escape,  and  part  of  the  muriate  sublimes. 

Most  of  the  metallic  and  vegetable  acids  dissolve  zinc 
which  is  precipitated  from  its  solution  by  earths  and  a' 


POTASSIUM.  129 

kalies;  the  latter  re-dissolves  the  precipitate,  if  added 
in  excess. 

Sulphur  cannot  be  made  to  combine  with  metallic 
zinc  ;  but  it  combines  readily  with  the  oxide  of  zinc. 

Zinc  may  be  combined  with  phosphorus  by  casting 
small  pieces  of  phosphorus  upon  the  melted  metal,  which 
should  be  covered  with  tallow  or  rosin  to  prevent  its 
oxidation.  Phosphuret  of  zinc  is  white,  with  a  shade  of 
bluish  grey,  has  a  metallic  lustre,  and  is  a  little  malleable. 

Zinc  also  combines  with  carbon,  and  forms  a  carburet 
of  zinc.  It  generally  contains  a  small  portion  ot  carbon. 

POTASSIUM. 

•  i 

Thk  fixed  alkalies,  potass  and  soda,  are  found  not  to 
be  simple  bodies,  as  had  once  been  supposed,  but  oxides, 
each  of  them  containing  a  peculiar  metal  in  combination 
with  oxygen.  They  were  analyzed  by  Sir  II.  Davy,  in 
a  course  of  experiments  which  that  distinguished  chemist 
undertook  with  the  express  view  of  discovering  their 
nature.  lie  succeeded  by  means  of  the  galvanic  appa¬ 
ratus  in  the  following  manner. 

In  his  first  experiments  he  acted  upon  aqueous  solutions 
of  potass  and  soda,  by  a  powerful  voltaic  combination, 
but  in  this  way  he  only  obtained  the  decomposition  of 
the  water  of  the  solution.  He  then  acted  upon  these 
alkalies  in  a  state  of  igneous  fusion.  The  potass  was 
contained  in  a  platina  spoon,  and  was  kept  perfectly 
fused  in  a  strong  red  heat,  by  means  of  a  stream  of 
oxygen  gas,  from  a  gasometer  applied  to  the  flame  of  a 
spirit-lamp.  The  spoon  was  preserved  in  communication 
vvith  the  positive  side  of  the  battery  of  the  power  of  100 
plates  of  0  inches,  highly  charged,  and  the  connection 
from  the  negative  side  was  made  by  a  platina  wire. 
The  advantage  of  this  arrangement  over  the  aqueous 
solution  was  soon  apparent.  The  potass  seemed  to  be  a 
conductor  in  a  high  degree,  and  as  long  as  the  communi¬ 
cation  was  preserved,  a  most  intense  light  wras  exhibited 
at  the  negative  ware,  and  a  column  of  flame,  which 


CHEMISTRY. 


130 

seemed  to  be  owing  to  the  development  of  combustible 
matter,  arose  from  the  point  of  contact.  When  the  order 
was  changed,  so  that  the  platina  spoon  was  made  nega¬ 
tive,  a  vivid  and  constant  light  appeared  at  the  opposite 
point ;  there  was  no  effect  of  inflammation  around  it,  but 
aeriform  globules,  which  inflamed  in  the  air,  rose  through 
the  potass. 

As  the  products  of  the  decomposition,  which  evidently 
appeared  to  have  taken  place  in  the  above  experiment, 
could  not  be  collected,  Sir  H.  Davy  determined  to  apply 
the  galvanic  electricity  to  the  alkali  in  its  usual  state.  A 
small  piece  of  potass,  moistened  a  little  by  the  breath, 
was  placed  upon  an  insulated  disc  ot  platina,  connected 
with  the  negative  side  of  a  battery  consisting  of  100 
plates  of  6  inches,  and  150  of  4  inches  square,  in  a  state 
of  intense  activity,  and  a  platina  wire,  communicating 
with  the  positive  side,  was  brought  in  contact  with  the 
upper  surface  of  the  alkali.  The  whole  apparatus  was 
in  the  open  air.  Under  these  circumstances,  a  vivid 
action  was  soon  observed  to  take  place.  The  potass 
began  to  fuse  at  both  its  points  of  electrization,  and  small 
globules,  having  a  high  metallic  lustre,  and  precisely  the 
same  in  characters  to  mercury,  appeared,  some  of  which 
burnt  with  explosion  and  bright  flame.  These  globules 
are  the  basis  of  potass,  which  has  received  the  name  of 
potassium,  and  appears  fully  entitled  to  rank  among  the 
metals,  as  we  shall  proceed  to  show. 

It  next  became  a  matter  of  considerable  difficulty  to 
preserve  and  confine  the  basis  of  potass,  in  order  to 
examine  its  properties.  Sir  II.  Davy  found,  at  length, 
that  in  recently  distilled  naphtha  it  may  be  preserved  for 
some  days,  and  that  its  physical  properties  may  easily  be 
examined  in  the  atmosphere,  when  it  is  covered  with  a 
thin  film  of  this  liquid. 

Potassium,  at  the  temperature  of  GO0,  is  only  imper¬ 
fectly  fluid;  at  70°  it  becomes  more  fluid;  at  100°  its 
fluidity  is  perfect,  so  that  different  globules  may  easily 
be  made  to  run  into  one.  At  50°  it  becomes  a  soft  and 
malleable  solid,  which  has  the  lustre  of  polished  silver 


POTASSIUM. 


131 

at  about  the  freezing,  point  of  water,  it  becomes  liaid 
and  brittle,  and  when  broken1  in  fragments,  exhibits  a 
crystallized  texture,  of  a  perfect  whiteness  and  high 
metallic  splendour.  To  be  converted  into  vapour,  it 
requires  a  temperature  approaching  to  that  of  a  red 
heat.  It  is  an  excellent  conductor  of  caloric  and  of 
electricity. 

Potassium  will  not  sink  in  doubly  distilled  naphtha, 
the  specific  gravity  of  which  is  770.  Its  specific  gravity 
is  to  that  of  mercury  as  10  to  223,  which  gives  a  pro¬ 
portion  to  that  of  water  nearly  as  6  to  10,  so  that  it  is 
the  lightest  fluid  body  known.  Its  levity  is  the  physical 
property  in  which  it  differs  most  materially  from  the  rest 
of  the  metals ;  yet  between  the  lightest  and  heaviest  of 
the  established  metals,  the  difference  is  not  much  less, 
than  between  the  lightest  of  the  established  metals  and 
potassium. 

When  potassium  is  introduced  into  oxymuriatic  acid 
gas,  it  burns  spontaneously,  with  a  bright  red  light,  and 
muriate  of  potass  is  formed.  When  thrown  upon  water 
it  decomposes  with  great  violence ;  an  instantaneous  ex 
plosion  is  produced,  with  a  brilliant  flame,  and  a  solution 
of  pure  potass  is  the  result.  When  a  globule  is  placed 
upon  ice,  not  even  the  solid  form  of  two  substances  can 
prevent  their  union ;  for  it  instantly  burns  with  a  bright 
flame,  and  a  deep  hole  is  made  in  the  ice  which  is  found 
to  contain  a  solution  of  potass.  When  a  globule  is 
dropped  upon  moistened  turmeric  paper,  it  instantly 
burns,  and  moves  rapidly  upon  the  paper,  as  if  in  search 
of  moisture,  leaving  behind  it  a  deep  reddish-brown 
trace. 

So  strong  is  the  attraction  of  the  basis  of  potass  for 
oxygen,  that  it  discovers  and  decomposes  the  small  quan¬ 
tities  of  water  contained  in  alcohol  and  ether,  even  when 
they  are  carefully  purified. 

When  potassium  is  thrown  into  the  mineral  acids,  it 
inflames,  and  burns  on  the  surface. 

In  sulphuric  acid,  sulphate  of  potass  is  formed;  in  ni¬ 
trous  acid,  nitrous  gas  is  disengaged,  and  nitrate  of 


CHEMISTRY. 


132 

potass  is  formed.  When  pressed  upon  a  piece  of  phos¬ 
phorus,-  there  is  a  considerable  action ;  the  two  sub 
stances  become  fluid  together,  burn,  and  produce  phos¬ 
phate  of  potass. 

When  a  globule  of  potassium  is  made  to  touch  a 
globule  of  mercury  about  twice  as  large,  they  combine, 
with  considerable  heat.  The  compound  is  fluid  at  the 
temperature  of  its  formation,  but  when  cool,  it  appears 
as  a  solid  metal,  similar  in  colour  to  silver.  If  this  alloy 
be  exposed  to  the  air,  it  rapidly  absorbs  oxygen;  potass, 
which  deliquesces  is  formed,  and  in  a  few  minutes  the 
mercury  is  found  pure  and  unaltered.  When  a  globule 
of  the  amalgam  is  thrown  into  water,  it  rapidly  decom¬ 
poses  it  with  a  hissing  noise ;  potass  is  formed,  hydrogen 
disengaged,  and  the  mercury  remains  free. 

The  amalgam  of  potassium  and  mercury  dissolved  all 
the  metals  that  were  exposed  to  it;  and  in  this  state  of 
union  mercury  acts  on  iron  and  platina. 

Potassium  combines  with  fusible  metals,  and  the  alloy 
has  a  higher  point  of  fusion  than  the  fusible  metal. 

Potassium  readily  reduces  the  metallic  oxides,  when 
heated  in  contact  with  them.  It  decomposes  common 
glass  by  a  gentle  heat,  and  at  a  red  heat  ellects  a  change 
even  in  the  purest  glass. 

From  a  variety  of  experiments,  Professor  Davy  con¬ 
cludes,  that  100  parts  of  potass,  consist  of  about  84  basis, 
and  10  oxygen.  ' 

SODIUM. 

When  soda  is  exposed  to  the  action  of  galvanic 
electricity,  in  the  same  manner  as  the  potass,  in  the 
experiment  above  stated,  a  metal  is  obtained  which  is  the 
basis  of  the  alkali,  and  is  called  sodium. 

Sodium  is  white,  and  opaque,  and  when  examined 
under  a  film  or  naphtha,  has  the  lustre  and  general  ap¬ 
pearance  of  silver.  It  is  exceedingly  malleable,  and  is 
much  softer  than  any  of  the  common  metallic  substances. 
A  globule  of  it  only  one-tenth  of  an  inch  in  diameter, 
is  easily  spread  over  the  surface  of  a  quarter  of  an  inch, 


SODIUM. 


t 


133 


and  this  property  does  not  diminish  when  it  is  cooled  to 
32°  of  Fahrenheit. 

By  strong  pressure,  globules  of  sodium  may  be  made 
to  adhere  and  combine  into  one  mass  ;  so  that  the  prop¬ 
erty  of  welding,  which  belongs  to  iron  and  platina  at  a 
white  heat  only,  is  possessed  by  this  substance  at  common 
temperatures. 

Sodium  conducts  caloric  and  electricity  in  a  similai 
manner  to  potassium,  and  small  globules  of  it  inflame  by 
the  voltaic  electrical  spark,  and  burn  with  bright  explo¬ 
sions.  It  is  preserved  under  distilled  naphtha  in  the 
same  manner  as  potassium. 

Its  specific  gravity  is  smewhat  le^  than  that  of  water, 
being  as  .9348  to  1.  It  is  therefore  heavier  than  potassi¬ 
um  ;  but  the  difference  is  so  small,  that  we  place  them  in 
the  order  in  which  they  were  discovered. 

Sodium  has  a  much  higher  point  of  fusion  than  potas¬ 
sium  :  its  parts  begin  to  lose  their  cohesion  at  about 
120°,  and  it  is  a  perfect  fluid  at  about  180° ;  so  that  it 
readily  fuses  under  boiling  naphtha. 

But,  though  so  easily  fused,  it  remains  in  a  state  of  ig¬ 
nition  at  the  point  of  fusion  of  plate  glass. 

The  chemical  phenomena  of  sodium  are  not  very  dif¬ 
ferent  from  those  of  potassium.  When  exposed  to  the 
atmosphere,  it  immediately  tarnishes,  and  becomes 
covered  with  a  white  crust,  which  deliquesces  much 
more  slowly  than  that  furnished  by  potassium. 

The  flame  that  sodium  produces  in  oxygen  gas  is 
white,  and  it  sends  forth  bright  sparks,  occasioning  a 
very  beautiful  effect.  In  common  air,  it  burns  with  light 
of  the  colour  of  that  produced  during  the  combustion  of 
charcoal,  but  much  brighter. 

When  introduced  into  oxymuriatic  acid  gas,  it  burns 
vividly,  with  numerous  scintillations  of  a  bright  red 
colour.  The  substance  produced  by  this  combustion  is 
muriate  of  soda,  (common  salt.) 

When  thrown  upon  water,  it  produces  a  violent  effer¬ 
vescence,  with  a  loud  hissing  noise ;  it  combines  with  the 
oxygen  of  the  water  to  form  soda,  and  the  hydrogen  of 
12 


CHEMISTRY. 


134 

the  water  is  disengaged.  This  experiment  exhibits  no 
luminous  appearance.  With  hot  water,  the  decompo¬ 
sition  is  violent,  and  a  few  scintillations  are  observed  at 
the  surface  of  the  fluid ;  but  this  is  owing  to  small  par¬ 
ticles  of  sodium,  which  are  thrown  out  of  the  water 
sufficiently  heated  to  burn  in  passing  through  the  at¬ 
mosphere. 

Sodium  decomposes  the  water  of  alcohol  and  ether,  in 
the  same  manner  as  the  water  in  these  fluids  is  decom¬ 
posed  by  potassium.  •  ' 

ft  acts  upon  strong  acids  with  great  energy.  With 
nitrous  acid,  a  vivid  inflammation  is  produced :  with 
muriatic  and  sulphuric  acids,  there  is  much  heat,  but  no 
light. 

Sodium,  in  its  action  upon  sulphur,  phosphorus,  and 
the  metals,  scarcely  differs  from  potassium.  It  com 
bines  with  sulphur  in  close  vessels  filled  with  the  vapou. 
of  naphtha,  with  a  vivid  light,  heat,  and  often  with  ex 
plosion.  The  sulphuret  is  of  a  deep  grey  colour. 

The  phosphuret  has  the  appearance  of  lead,  and 
forms  phosphate  of  soda  by  exposure  to  air,  or  by  com¬ 
bustion. 

One-fortieth  part  of  sodium  renders  mercury  a  fixed 
soda  of  the  colour  of  silver,  and  the  combination  is 
attended  with  a  considerable  degree  of  heat. 

It  makes  an  alloy  with  tin  without  changing  its  colour, 
and  it  acts  upon  lead  and  gold  when  heated.  In  its  state 
of  alloy,  it  is  soon  converted  into  soda  by  exposure  to  the 
air. 

Sir  IT.  Davy  concluded,  that  100  parts  of  soda  con¬ 
sist  of  70  or  77  of  sodium,  and  24  or  23  oxygen. 

In  concluding  the  communication  to  the  Royal  Society, 
from  which  the  preceding  view  of  the  properties  of 
potassium  and  sodium  is  derived,  Sir  II.  Davy  justly 
remarks,  that  an  immense  variety  of  objects  of  research 
is  presented  in  the  powers  and  affinities  of  the  new 
metals  produced  from  the  alkalies.  In  themselves  they 
will  undoubtedly  prove  powerful  agents  for  analysis;  and 
having  an  affinity  for  oxygen  stronger  than  any  other 


BISMUTH. 


135 


known  substances,  they  may  possibly  supersede  the  appli¬ 
cation  of  electricity  to  some  of  the  undecomposed  bodies. 

In  sciences  kindred  to  chemistry,  the  knowledge  of  the 
nature  of  alkalies,  and  the  analogies  arising  in  con¬ 
sequence,  will  open  many  new  views :  they  may  lead  tc 
the  solution  of  many  problems  in  geology,  and  show  that 
agents  may  have  operated  in  the  formation  of  rocks  and 
earths  which  have  not  hitherto  been  suspected  to  exist. 

BISMUTH. 

Bismuth  is  known  among  artisans  by  the  name  of 
tinglass.  It  is  a  metal  of  laminated  texture,  a  pale 
yellowish  re$J  colour;  not  ductile  or  malleable,  but 
reducible  to  powder  under  the  hammer.  Its  specific 
gravity  is  9.822  ;  its  hardness  is  6.  It  melts  at  the  heat 
of  400°. 

Bismuth  sublimes  when  heated  in  close  vessels ;  when 
allowed  to  cool  slowly,  it  crystallizes.  It  is  not  altered  by 
water,  and  though  it  tarnishes  by  exposure  to  the  air,  it 
is  not  much  changed. 

Bismuth  combines  with  most  of  the  metals ;  its  general 
effect  is  to  increase  their  fusibility.  The  alloy  of  bis¬ 
muth  and  platina  is  very  brittle.  When- exposed  to  the 
air,  it  assumes  a  purple,  violet,  or  blue  colour.  The  bis¬ 
muth  may  be  separated  by  beat. 

Equal  parts  of  bismuth  and  gold  form  a  brittle  alloy, 
not 'much  paler  than  gold. 

Equal  parts  of  bismuth  and  silver  form  a  brittle  alloy 
but  less  so  than  the  last.  The  specific  gravity  of  this 
and  the  last  alloy  is  greater  than  intermediate. 

The  amalgam  of  mercury  and  bismuth  is  more  fluid 
than  mercury,  and  has  the  property  of  dissolving  lead, 
without  having  its  fluidity  lessened. 

The  alloy  of  copper  and  bismuth  is  not  so  red  as 
copper. 

A  small  portion  of  bismuth  renders  tin  brighter,  hard¬ 
er,  and  more  sonorous:  it  is  often  therefore  an  ingredient 
in  pewter  Bismuth  remarkably  increases  the  fusion  of 


CHEMISTRY. 


136 

this  metal:  when  the  alloy  consists  of  equal  parts,  W 
melts  at  280°. 

Bismuth  does  not  combine  with  zinc,  and  its  alloy  with 
iron,  cobalt,  arsenic,  and  antimony,  is  unknown. 

The  alloy  of  lead  and  bismuth  is  of  a  dark  grey  colour 
a  close  grain,  and  very  brittle.  Eight  parts  of  bismuth, 
five  of  lead,  and  three  of  tin,  form  a  metal  which  melts 
at  a  heat  not  exceeding  that  of  boiling  water,  lea 
spoons  are  made  of  this  alloy,  to  surprise  those  unac 
quainted  with  their  nature  :  they  have  the  appearanci 
of  common  teaspoons,  but  are  melted  in  hot  water. 

Bismuth  expands  as  it  cools,  for  which  reason  it  is  wrell 
adapted  for  casting,  and  is  sometimes  added  in  the  com¬ 
position  for  printers’  types,  particularly  the  smaller  sizes, 
where  a  sharp  perfect  impression  from  the  mould  is  ot 
great  importance. 

Bismuth  may  be  used  in  cu pollution  instead  of  lead, 
and  would  for  this  purpose  be  preferable  to  lead,  were 
it  not  so  much  more  scarce  and  expensive. 

This  metal,  when  exposed  to  a  red  heat,  burns  with  a 
faint  blue  flame,  and  emits  yellowish  fumes,  which  when 
condensed,  form  what  are  called  Jlowers  of  bismuth . 
This  oxide  is  converted  into  a  greenish  glass  by  strong 
heat. 

The  sulphuric  acid,  when  concentrated  and  boiling 
has  a  slight  action  on  bismuth.  Sulphurous  acid  gas 
escapes,  and  part  of  the  metal  is  converted  into  a  white 
oxide.  The  sulphate  of  bismuth  does  not  crystallize, 
and  is  very  deliquescent.  >  ’ 

The  nitric  acid  exerts  a  vehement  action  on  bismuth. 
Much  heat,  with  a  large  quantity  of  nitrous  gas,  is 
evolved.  The  solution,  when  saturated,  affords  crystals 
as  it  cools.  This  nitrate  detonates  weakly,  and  leaves  a 
yellow  oxide  behind,  which  effloresces  in  tile  air. 

The  action  of  muriatic  acid  upon  bismuth  is  very  slow 
and  inconsiderable ;  and  even  foi  this  ellect  the  acid 
must  be  highly  concentrated. 

Water  precipitates  bismuth  from  all  its  solutions:  the 
precipitate,  which  is  a  beautiful  white,  is  when  well 


AllSfeNIC. 


137 


washed,  used  as  a  cosmetic,  under  the  name  of  magis- 
terv  of  bismuth.  It  lias,  however,  the  disadvantage  of 
turning  to  a  dark  colour,  by  a  very  slight  degree  of  sul¬ 
phurous  effluvia  ;  and,  as  the  metal  resembles  lead  in 
its  noxious  qualities,  and  is  seldom  free  from  arsenic,  like 
other  mineral  cosmetics,  it  cannot  be  used  without  dan¬ 
ger  to  the  skin  and  the  constitution. 

Magistery  of  bismuth  is  sometimes  mixed  with  poma¬ 
tum,  for  the  purpose  of  staining  the  hair  of  a  dark 
colour. 

Sulphur  combines  readily  with  bismuth  'by  fusion. 
The  sulphuret  of  bismuth  is  of  a  bluish-grey  colour,  and 
crystallizes  into  beautiful  tetrahedral  needles.  It  con¬ 
tains  15  parts  in  100  of  sulphur. 

Phosphorus,  dropped  into  melted  bismuth,  forms  a  phos- 
phuret  of  the  metal,  which  only  contains  about  4  parts' 
in  the  100  of  phosphorus. 

ARSENIC. 

Arsenic  is  of  a  brilliant  bluish-white  colour,  a  lami¬ 
nated  texture,  fusible,  and  very  brittle.  Its  specific  gra¬ 
vity  is  8.310;  its  hardness,  7.  It  soon  tarnishes  by 
exposure  to  the  air,  becoming  first  yellowish,  and  then 
black;  but,  if  immersed  in  alcohol,  its  metallic  lustre 
sutlers  no  diminution.  It  is  one  of  the  most  combustible 
metals,  burns  with  a  blue  flame  and  the  smell  of  garlic, 
and  sublimes  in  a  state  of  arsenious  acid.  It  is,  in  all 
states,  one  of  the  most  virulent  poisons  known. 

When  exposed  to  the  air,  arsenic  is  gradually  con¬ 
verted,  by  combining  with  oxygen,  into  a  greyish-black 
substance,  which  is  the  grey  oxide  of  arsenic.  If  this 
oxide  be  sublimed,  the  sublimate,  having  combined  with 
an  additional  dose  of  oxygen,  forms  the  white  oxide  of 
arsenic,  which  contains  7  parts  in  the  100  of  oxygen. 
This  oxide  glitters  as  if  it  were  powdered  glass ;  it  has 
an  acid  taste,  which  terminates  in  an  impression  of  sweet¬ 
ness:  it  has  a  smell  like  garlic.  This  is  the  state  »c 
which  the  arsenic  of  commerce  is  met  with. 

12* 


138  CHEMISTRY. 

The  white  oxide  of  arsenic  maybe  converted  into  the 
metallic  state  by  heating  it  with  the  oils,  tallow,  or  char¬ 
coal,  in  close  vessels;  but  this  is  seldom  necessary  in  the 
arts,  as  it  enters  into  combination  with  other  metals  from 
the  state  of  oxide.  This  oxide  is  soluble  in  80  parts  of 
water,  at  the  temperature  ot  60°,  and  in  15  parts  of 
boiling  wafer.  When  the  solution  is  evaporated,  the 
oxide  crystallizes;  and  when  heated  to  28o  it  sublimes, 
if  heated  in  close  vessels,  it  becomes  pellucid  like  glass, 
but  soon  recovers  its  former  appearance  by  exposure  to 
the  air.  The  specific  gravity  of  the  glass  is  5.000  ;  of 

the  white  oxide  3.70G.  #  . 

Almost  the  whole  of  the  arsenic  which  is  sold,  is  ob¬ 
tained  from  the  cobalt  ores  of  Saxony,  where  long  winding 
flues  are  constructed,  to  the  sides  of  which  the  sublimed 

arsenic  attaches  itself.  , 

Arsenic  unites  with  most  of  the  metals  by  fusion,  and 
a  verv  small  quantity  of  it  has  often  a  material  effect. 

Platina  and  arsenic  form  a  brittle  and  fusible  alloy ; 
the  arsenic  may  be  driven  off  by  a  great  heat.  . 

Gold  by  fusion  takes  up  about  ¥Vth  of  arsemc»  Wlth 
which  it  forms  a  pale  and  brittle  alloy. 

Silver  takes,  up  one-fourteenth  of  arsenic. 

Copper  combines  with  five-sixths  of  arsenic,  forming  a 
white1,  hard,  and  brittle  alloy ;  when  the  quantity  is  small, 
it  is  both  ductile  and  malleable;  it  is  called  white  tombac, 
and  is  much  used  in  the  manufacture  of  buttons. . 

Iron  is  capable  of  combining  with  more  than  its  own 
weight  of  arsenic  ;  the  alloy  is  white,  brittle,  and  capable 
of  crystallization. 

The  alloy  of  tin  and  arsenic  is  harder  and  more 
sonorous  than  tin,  and  has  nearly  the  same  external 
appearance  as  zinc.  Tin  often  contains  a  small  quantity 
of  arsenic.  * 

Lead  takes  up  one-sixth  of  arsenic,  lhe  alloy  is 
.irittle  and  dark  coloured. 

Zinc  takes  up  one-fifth  of  arsenic,  antimony  one-eighth, 

and  bismuth  one-fifteenth.  _ 

Upon  the  whole,  the  effect  of  arsenic  is,  to  whiten  tie 


ARSENIC. 


139 

red  and  dark  coloured  metals;  to  give  brittleness  to  the 
ductile  ;  to  increase  the  fusibility  of  the  refractory,  and 
o  render  less  fusible  the  rest.  It  is  added  to  the  com¬ 
positions  of  the  mirrors  of  reflecting  telescopes,  to  increase 
the  density  of  the  compound. 

The  sulphuric  acid,  boiled  on  the  oxide  of  arsenic, 
dissolves  it ;  but  the  oxide  precipitates  as  the  solution 
cools. 

The  nitric  acid  dissolves  the  oxide  of  arsenic,  by  the 
assistance  of  heat,  and  forms  a  deliquescent  salt. 

The  action  of  muriatic  acid  upon  arsenic  is  very 
feeble,  whether  assisted  by  heat  or  in  the  cold.  The 
sublimed  muriate  or  butter  of  arsenic,  is  formed  by  mix¬ 
ing  equal  parts  of  the  yellow  oxide  of  arsenic,  and  corro¬ 
sive  muriate  of  mercury,  and  distilling  with  a  gentle 
heat ;  in  the  receiver  will  be  found  a  blackish  corrosive 
liquor,  which  forms  the  sublimed  muriate  of  arsenic. 

Potass,  boiled  on  the  oxide  of  arsenic,  becomes  brown, 
gradually  thickens,  and  at  last  forms  a  hard  brittle  mass, 
which  is  deliquescent  arsenical  salt.  Soda  affords,  by 
the  same  treatment,  a  product  nearly  similar. 

The  combination  of  arsenic  and  sulphur  is  often  found 
native,  of  a  fine  yellow  colour;  it  is  then  called  orpi- 
ment ;  this  yellow  sulphuret  of  arsenic  maybe  prepared 
artificially,  by  mixing  sulphur  with  the  white  oxide  of 
arsenic,  and  heating  them.  It  contains  about  20  parts 
of  arsenic  in  the  100.  If  a  stronger  heat  be  applied,  so 
as  to  fuse  this  sulphuret,  it  assumes  a  scarlet  colour,  and 
forms  the  compound  called  realgar,  which  contains  80 
parts  of  arsenic  in  the  100.  It  is  the  red  sulphuret  of 
arsenic.  Realgar  is  occasionally  found  native,  as  well  a 
orpiment.  Lime  and  the  alkalies  decompose  these  sul 
phurets. 

The  phosphuret  of  arsenic  may  be  found  by,  putting 
equal  parts  of  phosphoret  and  arsenic  into  a  sufiicient 
quantity  of  water,  and  keeping  the  mixture  moderately 
hot  some  time.  It  is  black  and  brilliant,  and  ought  to  ba 
preserved  in  water. 

The  oxide  of  arsenic  promotes  the  vitrificatiois  of 


CHEMISTRY. 


110 

earths,  hut  the  glasses  into  which  it  enters  arc  liable  to 
tarnish. 

The  workmen  employed  in  the  mines  which  produce 
arsenic,  are  subject  to  violent  complaints,  and  premature 
death.  When  this  deleterious  mineral  has  been  swal¬ 
lowed,  the  sulphuret  of  potass  (liver  ol  sulphur)  dis¬ 
solved  in  water,  is  prescribed  as  the  most  clfectual  anti¬ 
dote.  Arsenic,  whether  alone  or  in  a  mixture,  may  he 
distinguished  by  throwing  it  upon  burning  coals;  as  it 
will  alford  white  fumes  and  the  smell  of  garlic. 

ANTIMONY. 

Antimony  is  a  brittle  metal,  of  a  white  colour,  inclin¬ 
ing  to  grey,  a  laminated  texture,  exceedingly  brittle,  and 
neither  malleable  nor  ductile.  It  may  be  reduced  to 
powder.  It  has  some  taste,  but  no  smell.  Its  specific 
gravity  is  G.8G0 ;  its  hardness,  G.5.  It  tarnishes  but  little 
by  the  action  of  the  air  or  water.  It  melts  at  a  low  red 
heat,  or  809° ;  and,  if  the  heat  be  much  increased,  it  is 
volatilized  in  white  fumes.  This  white  oxide  ot  anti¬ 
mony  was  formerly  called  argentine  snow,  or  flower's  of 
antimony. 

If  antimony  be  brought  to  a  white  heat,  and  then 
shaken,  it  takes  tire,  with  a  kind  of  explosion.  If  fused 
on  charcoal  before  the  blow-pipe,  and  thrown  into  the 
air,  it  divides  into  globules,  and  burns  with  a  brilliant 
white  light  as  it  falls  to  the  ground. 

The  antimony  of  commerce  is  found  in  two  states — 
that  of  crude  antimony,  and  in  the  metallic  state.  Crude 
antimony  is  the  sulphuret  of  this  metal,  and  is  the  only 
ore  of  it  which  is  obtained  in  sufficient  quantity  to  be 
wrought.  Metallic  antimony,  better  known  by  the  name 
of  regains,  is  crude  antimony  deprived  of  its  sulphur. 
If  iron  tilings  be  fused  with  crude  antimony,  they  com 
bine  with  its  sulphur,  and  the  antimony  is  obtained  pure. 
One-fifth  of  iron  will  combine  with  all  the  sulphur  by 
which  this  metal  is  mineralized.  In  the  large  way,  an¬ 
timony  is  obtained  by  melting  calcined  antimony  with 


ANTIMONY. 


141 


dried  wine-lees,  in  a  reverberatory  furnace,  and  the  sub 
phur  is  often  not  wholly  removed  from  it.  Sulphuret  o* 
antimony  contains  26  parts  in  the  100  of  the  metal. 

Antimony  will  enter  into  combination  with  most  oi 
the  metals.  With  piatina,  it  affords  a  brittle  alloy,  which 
is  much  lighter  than  piatina.  The  piatina  cannot  after¬ 
wards  be  separated  from  it  by  heat. 

Gold  may  be  combined  with  antimony,  by  fusing  them 
together;  and  the  antimony  may  be  separated  by  an  in¬ 
tense  heat. 

Silver  and  antimony  form  a  brittle  alloy,  the  specilic 
gravity  of  which  is  greater  than  intermediate  between 
the  specific  gravities  of  the  two  metals. 

Mercury  does  not  combine  freely  with  antimony.  Gel- 
lert  succeeded  by  using  hot  mercury,  and  covering  the 
whole  with  water. 

Equal  parts  of  lead  and  antimony,  form  a  porous  and 
brittle  alloy ;  three  parts  of  lead  and  one  of  antimony  is 
the  best  composition  for  printing-types;  and  of  all  the 
alloys  of  antimony  is  the  most  useful.  It  forms  a  hard 
alloy,  scarcely  malleable,  but  so  brittle  as  to  break  with¬ 
out  bending,  unless  in  very  slender  pieces;  when  pro¬ 
perly  prepared,  its  fracture  has  the  appearance  of  that 
of  cast-steel.  In  fusing  the  two  metals,  the  antimony 
should  be  well  mixed  by  stirring,  as  from  its  levity  it 
will  float  on  the  lead  ;  if  the  mixture  has  not  been  com¬ 
plete,  the  alloy  breaks  with  brilliant  facets.  This  alloy 
is  more  fusible  and  fluid  than  either  of  the  metals  sepa¬ 
rately,  and  as  antimony  expands  in  cooling,  it  takes  a 
sharp  impression  of  a  mould.  Bismuth  is  sometimes 
added  to  increase  this  property,  as  well  as  the  fusibility 
but  this  metal  is  too  costly  to  be  added  in- any  useful  pro¬ 
portion,  except  for  the  smallest  types.  The  antimony 
should  be  completely  freed  from  sulphur,  otherwise  the 
types  made  of  it  undergo  a  spontaneous  decomposition, 
easily  break,  and  are  covered  with  a  black  crust. 

Twelve  parts  of  lead  and  one  of  antimony,  lorm  an 
alloy  very  malleable;  yet  much  harder  than  lead ;  10 
parts  of  lead  and  one  of  antimony,  form  an  alloy  which 
does  not  differ  from  lead,  except  in  being  rather  harder 


CHEMISTRY. 


142 

Copper  combines  readily  with  antimony;  the  colour  of 
the  alloy  is  a  beautiful  violet,  and  its  specific  gravity  is 
greater  than  intermediate. 

The  alloy  formed  by  iron  and  antimony  is  brittle  and 
hard ;  its  specific  gravity  is  less  than  intermediate.  The 
disposition  'of  iron  to  receive  magnetism,  is  much  im¬ 
paired  by  antimony. 

The  alloy  of  tin  and  antimony  is  harder  than  tin 
white,  and  brittle:  the  specific  gravity  is  less  than  inter¬ 
mediate,  yet  the  combination  is  so  intimate,  that  it  is 
scarcely  possible  to  separate  the  antimony  from  the  tin. 
A  small  portion  of  antimony  is  added  with  tin  to  form 
pewter. 

Le  Sage  analyzed  some  nails  intended  for  ship-build¬ 
ing,  and  found  them  to  consist  three  parts  tin,  two  of 
lead,  and  one  of  antimony.  These  nails  could  be  made 
to  penetrate  oak  boards,  and  were  not  acted  upon  by 
sea-water. 

The  alloy  of  zinc  and  antimony  is  brittle. 

Pure  pewter  has  some  action  upon  antimony,  for  it 
becomes  purgative  by  standing  in  a  vessel  made  of  this 
metal. 

Sulphuric  acid,  boiled  upon  antimony,  is  slowly  de¬ 
composed.  Sulphurous  gas  escapes,  and  sulphur,  itself, 
by  continuing  the  process.  The  sulphate  of  antimony  is 
deliquescent,  and  decomposed  by  the  fire. 

The  nitric  acid  is  decomposed  by  antimony  very  readi¬ 
ly;  a  considerable  part  of  the  antimony  is  oxidized,  and 
part  of  the  oxide  is  dissolved.  This  oxide  is  very  white, 
and  difficult  of  reduction. 

The  muriatic  acid  acts  freely  upon  antimony,  except 
by  long  digestion.  The  muriate  of  antimony,  obtained 
by  evaporation,  is  very  deliquescent :  it  is  fusible  in  the 
fire,  and  volatile. 

Two  parts  of  corrosive  muriate  of  mercury,  and  one 
of  the  muriate  of  antimony,  distilled  by  a  gentle  heat, 
afford  tire  common  butter  of  antimony,  or  sublimed  mu¬ 
riate  of  antimony.  This  preparation  is  lluid  at  a  gen¬ 
tle  heat;  by  plunging  the  vessel  which  contains  it  intc 
hot  water,  it  becomes  sufficiently  fluid  to  pcur  out. 


ANTIMONY. 


143 


When  butter  of  antimony  is  dropped  into  water,  part 
of  the  metal,  in  the  form  of  an  oxide,  is  thrown  down  in 
a  white  powder.  This  substance  is  called  powder  of 
algaroth,  which  acts  as  a  strong  purgative. 

If  sulphuret  of  antimony  be  melted,  and  the  boat  con¬ 
tinued,  the  sulphur  sublimes,  and  the  antimony  is  con¬ 
verted  into  a  grey  oxide;  this  oxide  may  likewise  be 
obtained  by  powdering  metallic  antimony,  and  then 
submitting  it  to  calcination.  The  oxide  will  combine 
with  of  sulphur,  and  this  compound  forms,  by  fusion, 
a  glass  called  the  glass  of  antimony. 

Antimony  supplies  medicine  with  some  of  the  most 
active  and  valuable  remedies.  The  acid  of  tartar  forms 
with  it  the  preparation  called  emetic  tartar ,  the  new 
name  of  which  is  antimoniated  tartrate  of  potass :  it  is 
composed  of  50  parts  tartrate  of  antimony,  86  tartrate 
of  potass,  and  S  of  water. 

The  alkalies  and  lime  decompose  the  antimoniated 
tartrate  of  potass. 

The  alkalies  alone  have  no  perceptible  action  on  anti¬ 
mony,  but  the  alkaline  sulphurets  dissolve  it  completely. 
Kermes’  mineral,  a  medicine  formerly  of  great  celebrity, 
is  a  red  sulphuretted  oxide  of  antimony.  It  is  prepared 
by  boiling  together  half  a  pound  of  the*  sulphuret  of 
antimony  in  powder,  and  two  pounds  of  potass,  in  eight 
pints  of  pure  water,  for  fifteen  minutes;  stirring  the  mix¬ 
ture  with  an  iron  spatula ;  and  then  expeditiously  filter¬ 
ing  it  whilst  it  is  hot.  The  liquor  is  now  suffered  to  stand 
in  a  cool  place,  where  it  soon  deposits  a  powder  that 
must  be  repeatedly  washed,  first  with  cold,  and  after¬ 
wards  with  hot  water,  till  deprived  of  taste.  The  anti¬ 
mony  may  be  used  again,  until  entirely  consumed.  Ac¬ 
cording  to  the  quantity  which  is  taken,  Kermes’  mineral 
operates  as  an  emetic,  purgative,  sudorific,  or  expecto¬ 
rant  ;  its.  active  properties  render  half  a  grain  in  most 
cases  sufficient  at  a  time. 

Phosphorus,  thrown  in  small  pieces  upon  melted  anti¬ 
mony,  combines  with  it.  The  phosphuret  of  antimony, 
is  of  a  white  colour,  brittle,  and  appears  laminated  when 
broken.  •  • 


144 


CHEMISTRY. 


TELLURIUM. 

Tellurium  is  a  recently  discovered  metal,  nearly  white 
like  tin,  but  varying  a  little  to  the  greyness  of  lead.  Its 
fracture  is  laminated.  It  is  extremely  brittle,  and  nearly 
as  fusible  as  lead.  When  heated  with  the  blow-pipe 
upon  charcoal,  it  burns  with  a  very  lively  flame,  of  a 
blue  colour,  inclining  at  the  -edges  to  green.  It  is  so 
volatile  as  to  rise  entirely  into  a  whitish  grey  smoke, 
and  exhales  an  odour  like  that  of  radishes.  The  smoke 
condenses  into  a  white  oxide.  Its  specific  gravity  is 
G.115. 

Klaproth,  who  discovered  this  metal,  found  it  in  an  ore 
called  the  auriferous  ore,  otherwise  aurum  paradoxicum , 
which  is  obtained  in  Transylvania,  and  which  contains 
but  a  very  small  quantity  ot  gold. 

Tellurium  amalgamates  with  mercury  by  trituration. 
It  is  oxidized  and  dissolved  in  the  principal  acids.  To 
sulphuric  acid  it  gives  a  deep  purple  colour,  and  if  this 
acid  has  been  diluted  with  two  or  three  parts  of  water, 
and  a  little  nitric  acid  added,  a  considerable  portion  of 
tellurium  will  dissolve  in  it,  and  the  solution  will  not  be 
decomposed  by  water.  The  solution  in  sulphuric  acid 
alone  is  separntcd  in  black  flakes,  and  heat  throws  down 
a  white  precipitate. 

With  nitric  acid,  tellurium  forms  a  colourless  solution, 
which  remains  so  when  diluted,  and  affords  slender,  den¬ 
dritic  crystals  by  evaporation. 

Tellurium  dissolves  in  nitro-muriatic  acid  ;  the  solution 
is  transparent,  and  the  addition  of  water  precipitates  a 
white  powder,  which  is  soluble  in  muriatic  acid.  Alcohol 
produces  a  similar  precipitate. 

Iron,  tin,  zinc,  and  antimony,  precipitate  tellurium 
from  its  acid  solutions  in  a  metallic  state,  under  the  form 
of  small  black  flakes,  which  resume  their  splendour  by 
friction,  and  which  on  burning  charcoal  rapidly  melt  into 
a  metallic  button. 

The  alkalies  throw  down  from  the  solutions  of  telluri¬ 
um,  a  white  precipitate,  which  is  soluble  in  all  the  acid.-, 

bv  an  excess  of  the  alkalies  or  their  carbonates 
*/ 


TUNGSTEN. 


145 


TUNGSTEN. 

Tungsten  is  externally  of  a  brown  colour,  internally 
of  a  steel  grey.  Its  specific  gravity  is  17.G00,  and  it 
is  extremely  difficult  of  fusion. 

This  metal  is  in  Sweden  obtained  from  an  ore  in  which 
its  oxide  exists  in  combination  with  lime ;  in  Germany 
and  England,  it  may  be  obtained  from  a  mineral  called 
wolfram,  in  which  it  exists  in  combination  with  iron. 
The  oxide  of  tungsten  has  acid  properties,  and  is  there¬ 
fore  called  tungstic  acid. 

D’Elhuyart  found  that  wolfram  contained  of  tung¬ 
stic  acid  ;  the  rest  of  it  consisted  of  iron,  manganese,  and 
tin.  This  acid  substance  being  mixed  with  charcoal 
powder,  was  violently  heated  in  a  crucible:  after  it  had 
cooled,  a  button  of  metal  was  found  of  a  dark  brown 
colour,  which  crumbled  to  pieces  between  the  fingers. 
On  viewing  it  with  a  glass,  it  was  found  to  consist  of  a 
congeries  of  metallic  globules,  some  of  which  were  as 
large  as  a  pin  head.  These  globules  were  the  tungsten ; 
the  charcoal  had  combined  with  the  oxygen  of  the  acid 
substance,  and  left  the  metal  pure.  When  heat  is  ap¬ 
plied  with  access  of  air,  tungsten  is  converted  into  a 
yellow  powder,  composed  of  80  parts  of  tungsten,  and 
20  of  oxygen.  This  is  the  yellow  oxide  of  tungsten ,  or 
tungstic  acid. 

Vauquelin  considers  that  the  substance  formed  by 
combination  of  tungsten  with  oxygen,  does  not  possess 
the  properties  generally  attributed  to  acids ;  since  it  is 
insoluble  in  water,  does  not  change  the  blue  vegetable 
colours,  and  has  no  apparent  savour.  He  advises  it 
therefore  to  be  called  merely  an  oxide  of  tungsten,  ob¬ 
serving  that  Scheele,  who  regarded  it  as  an  acid,  never 
obtained  it  but  in  a  triple  combination,  which  possesses 
a:id  properties. 

Morveau  asserts  that  the  oxide  of  tungsten  renders 
vegetable  colours  so  fixed  as  not  to  be  acted  upon  by  the 
oxy  muriatic  acid. 

13 


K 


CHEMISTRY. 


146 

Neither  the  sulphuric,  the  nitric,  nor  the  muriatic 
acid  dissolves  either  tungsten  or  its  oxide. 

The  alloys  of  tungsten,  and  the  uses  to  which  the 
metal  itself  ltiaybe  applied,  appear  to  be  little  known. 

Solutions  of  caustic  potass,  soda,  and  ammonia, 
dissolve  the  oxide  of  tungsten,  even  in  the  cold,  forni- 
ing'tungstate  of  potass,  soda,  and  ammonia. 

Tungsten  refuses  to  unite  with  sulphur. 

A  tungstate  of  magnesia  is  formed,  by  mixing  oxide 
of  tungsten  with  carbonate  of  magnesia  and  water, 
boiling  the  mixture,  and  straining  it.  An  acid  will 
precipitate  a  white  powder;  and,  by  evaporation,  a 
white  salt  is  obtained,  which  crystallizes  in  little 
bright  spangles,  and  is  unchangeable  in  air. 

RHODIUM. 

Rhodium  is  one  of  the  new  metals  obtained  from 
grains  of  crude  platina.  Its  specific  gravity  is  about 
11.  It  is  not  malleable,  and  has  never  been  perfectly 
fused  alone.  Sulphur  and  arsenic  render  it  fusible, 
and  may  afterwards  be  expelled  by  heat. 

Rhodium  unites  readily  with  every  metal  which  Dr. 
'VYobaston,  its  discoverer,  tried,  except  mercury.  With 
gold  or  silver,  the  alloy  is  malleable,  not  oxidized  by  a 
high  degree  of  heat,  but  becoming  encrusted  with  a 
black  oxide  when  slowly  cooled.  One  sixth  of  it  does 
not  perceptibly  alter  the  colour  of  gold,  but  renders  it 
much  less  fusible.  Neither  the  nitric,  nor  the  nitro-mu- 
riatic  acid  acts  on  it  in  the  state  of  alloy  with  gold 
silver,  but,  if  it  be  fused  with  three  parts  of  bismuth, 
lead  or  copper,  the  alloy  is  entirely  soluble  in  a  mix¬ 
ture  of  nitric,  mixed  with  two  parts  of  muriatic  acid. 

URANIUM. 

Uranium  is  of  a  dark  grey  color  on  the  surface, 
within,  it  is  a  pale  brown.  Its  hardness  is  about  G.  It 
is  more  difficult  of  fusion  than  manganese.  It  is  little 


COBALT. 


14? 

known,  and  appears  not  to  be  obtained  in  a  state  of 
purity,  as  tile  specimens  of  different  chemists  have 
varied  in  specific  gravity  from  6.440  to  9.000. 

Klaproth  discovered  uranium  in  a  mineral  called 
peach-blend,  which  is  obtained  in  Saxony,  and  which  had 
oeen  usually  considered  as  an  ore  of  zinc  or  iron,  or  even 
tungsten  ;  but  Klaproth’s  analysis  evinced  that  it  was  the 
sulpburet  of  uranium. 

When  exposed  for  some  time  to  a  red  heat,  in  a  close 
vessel,  uranium  suffers  no  change ;  but  by  means  of 
nitric  acid,  it  is  converted  into  a  yellow  oxide.  This 
oxide  is  soluble  in  diluted  sulphuric  acid  gently  heated, 
and  affords  prismatic  crystals  of  a  lemon  colour.  It  is 
also  soluble  in  nitromuriatic  acid,  and  may  be  precipi 
tated  by  alkalies. 

COBALT. 

Cobalt  is  of  a  whitish  colour,  inclining  to  a  bluish  or 
steel  grey.  When  pure,  it  is  somewhat  malleable  while 
red  hot,  and  is  also  attracted  by  the  magnet  Its  hard¬ 
ness  is  8,  and  its  specific  gravity  is  usually  about  7.811. 
It  is  brittle,  and  has  a  dull,  close-grained  fracture.  It  is 
not  acted  upon  by  water,  but  tarnishes  in  the  air ;  it 
requires,  for  its  fusion,  a  heat  not  inferior  to  that  for  cast- 
iron.  It  has  never  been  volatilized. 

Cobalt  has  been  found  native;  but  mostly  in  the  state 
of  an  oxide,  united  with  arsenic,  sulphur,  iron,  &c.  It 
is  plentiful  in  the  mines  of  Saxony;  and  is  also  abun¬ 
dantly  obtained  in  the  Mendip  Hills,  Somersetshire,  Eng-  . 
land,  and  in  a  mine  near  Penzance,  in  Cornwall. 

Arsenical  cobalt  is  of  a  greyish  colour,  and  becomes 
black  by  exposure  to  air.  The  sulphurous  ore  of  cobalt 
resembles  the  grey  silver  ore  in  its  texture. 

When  the  oxide  of  cobalt  has  been  freed  from  arsenic 
and  sulphur,  which  is  done  by  pulverizing  it,  washing  it, 
and  then  exposing  it  to  a  strong  heat,  it  has  an  obscure 
grey  colour,  and  is  called  zajfre.  When  zaffre  is  fused 
with  three  parts  of  pulverized  flints,  and  one  of  potass 
a  beautilul  blue  glass  is  obtained.  This  glass,  when 


CHEMISTRY. 


148 

pulverized  and  washed,  constitutes  the  smalt  of  com¬ 
merce.  Smalt  is  used  to  give  the  blue  colour  to  writing 
paper,  to  starch,  and  linen.  It  also  supplies  a  blue  colour 
to  the  painters  of  earthenware  and  porcelain,  and  to 
-  enamellers. 

Metallic  cobalt  may  be  obtained  by  fusing  zaffre  in  a 
white  heat,  with  three  times  its  weight  of  black  flux 
the  cobalt,  when  reduced,  sinks  to  the  bottom  of  the  cru 
cible.  Or  it  may  be  obtained  by  fusing  smalt  with  six  or 
eight  times  its  weight  of  soda. 

Cobalt  resists  cupellation,  nor  will  it  amalgamate  with 
mercury,  it  forms  alloys  with  few  of  the  metals:  that 
with  tin  is  of  a  light  violet  colour.  The  metals  with 
which  it  combines  most  readily  are  arsenic  and  iron: 
these,  when  combined  with  it,  are  separated  with  diffi¬ 
culty.  With  iron,  the  alloy  is  hard,  and  not  easily 
broken:  with  arsenic,  it  is  brittle, fusible, and  more  easily 
oxidized  than  pure  cobalt. 

To  dissolve  cobalt  in  sulphuric  acid,  the  acid  must  be 
concentrated,  and  distilled  upon  it  almost  to  dryness. 
By  washing  the  residuum,  a  portion  of  it  dissolves  in  the 
water:  this  portion  is  sulphate  of  cobalt.  The  other 
part  consists  of  oxide  of  cobalt.  The  cobalt  may  be 
precipitated  from  the  water  by  lime  and  alkalies. 

Nitric  acid  dissolves  cobalt  by  the  assistance  of  a  gen 
tie  heat.  Lime  and  alkalies  precipitate  it  from  its  solu 
tion ;  and  an  excess  of  alkali  dissolves  the  precipitate. 

Muriatic  acid  does  not  dissolve  cobalt  without  the 
assistance  of  heat.  The  nitro-muriatic  acid  dissolves 
cobalt  more  readily.  This  solution,  much  diluted,  forms 
the  much-admired  sympathetic  ink,  which,  when  written 
with  upon  paper,  is  invisible ;  but,  when  the  paper  is 
warmed,  the  characters  appear  of  a  beautiful  green, 
that  gradually  disappears  as  the  paper  cools ;  and  the 
experiment  may  be  repeated  with  the  same  result  for  an 
indefinite  number  of  times. 

Sulphur  is  not  readily  combined  with  cobalt  by  art ; 
but  alkaline  sulphurets  readily  form  the  combination. 

The  phosphuret  of  cobalt  may  be  formed  by  dropping 


MOLYBDENUM. 


149 


small  pieces  of  phosphorus  upon  ignited  cobalt  in  grains. 
It  is  white  and  brittle,  and  soon  loses  its  lustre  by  expo¬ 
sure  to  the  air :  it  is  more  fusible  than  cobalt. 

MOLYBDENUM. 

The  ore  containing  molybdenum  has  almost  the  ap¬ 
pearance  of  plumbago,  and  therefore,  though  scaly  and 
more  shining,  it  was,  before  it  was  carefully  analyzed, 
mistaken  for  that  mineral.  It  is  unctuous  to  the  touch, 
soils  the  fingers,  and  makes  whitish  and  brilliant  traces 
upon  paper,  whereas  the  traces  of  plumbago  are  dull. 
It  has  never  been  perfectly  reduced  ;  when  made  into  a 
paste  with  linseed  oil,  or  any  other  suitable  substance, 
the  strongest  fires  only  agglutinate  it  in  brittle  masses, 
consisting  of  small  grains.  These  grains  are  of  a  whitish 
yellow  colour,  but  their  fracture  is  a  whitish  grey.  Their 
specific  gravity  is  at  least  7.500. 

The  alloys  of  molybdenum  have  been  little  examined  ; 
those  with  silver,  iron,  and  copper,  are  friable;  those 
with  lead  and  tin  pulverulent  and  fusible. 

Molybdenum,  by  a  strong  heat,  is  gradually  converted 
into  a  whitish  coloured  oxide.  Nitric  acid,  which  has  a 
rapid  action  upon  it,  converts  it  into  a  white  oxide.  This 
oxide  has  the  properties  of  an  acid,  and  is  therefore  called 
molybdic  acid.  It  dissolves  in  576  parts  of  water  at  a 
mean  temperature.  It  decomposes  the  solutions  of  scap, 
and  precipitates  alkaline  sulphurets. 

Thd  muriatic  acid  has  no  action  upon  molybdenum, 
but  dissolves  its  acid,  which  is  also  done  by  the  sulphuric. 
Heat  should  be  employed  with  both  these  acids. 

Scheele  discovered,  1,  that  fixed  alkali  rendered 
molybdic  acid  more  soluble  in  water;  2,  that  salt  pre¬ 
vents  the  acid  of  molybdenum  from  volatilization  by 
heat ;  3,  that  molybdate  of  potass  falls  down  by  cooling, 
in  small  crystalline  grains,  and  that  it  may  likewise  be 
separated  from  its  solvent  by  sulphuric  and  muriatic 
acids. 

Blue  carmine  is  prepared  by  precipitating  tin  from  its 
13  * 


150 


CHEMISTRY. 


solution  in  muriatic  acid  with  the  molybdate  of  potass. 
The  muriatic  acid  unites  with  the  alkali,  and  the  molyb- 
dic  with  the  tin,  to  form  the  blue  precipitate. 

MANGANESE. 

A  mineral,  called  the  soap  of  glass,  has  been  employed 
for  time  immemorial  in  the  manufacture  of  glass,  which 
it  whitens  and  renders  colourless.  It  is  usually  of  a  grey 
or  blackish  colour,  and  soils  the  fingers.  This  mineral  is 
the  oxide  of  a  peculiar  metal  called  manganese. 

Metallic  manganese  is  of  a  greyish  white  colour,  brit¬ 
tle,  though  not  easily  broken,  and  devoid  of  malleability. 
When  reduced  to  powder,  it  is  attracted  by  the  magnet. 
Its  specific  gravity  is  G.990 ;  its  hardness  is  8.  It  is  more 
difiicult  of  fusion  than  iron. 

When  manganese  is  exposed  to  the  atmosphere,  it  soon 
tarnishes,  and  becomes  at  last  black  and  friable;  heat 
accelerates  this  change ;  which  produces  the  substance 
called  black  oxide  of  manganese.  It  is  this  oxide  of  the 
metal  which  is  usually  employed  in  the  arts,  and  in  which 
state  manganese  is  generally  found.  The  counties  of 
Somerset  and  Devon  supply  large  quantities  of  it,  and  in 
the  vicinity  of  Aberdeen,  a  mine  of  it  has  been  lately 
discovered,  which  furnishes  twenty  tons  per  week. 

The  black  oxide  of  manganese  contains  25  per  cent, 
of  oxygen;  a  portion  of  this  oxygen  is  separated  by  heat, 
and,  therefore,  the  oxide  has  recently  become  important, 
for  the  purpose  of  furnishing  this  gas.  When  manganese 
is  employed  in  preparing  oxymuriatic  acid  for  medicine, 
the  purest,  such  as  that  from  Upton  Pyne,  should  be 
used.  That  from  Bristol  and  the  Mendip  Hills,  generally 
contains  lead. 

Manganese  is  susceptible  of  three  different  degrees  of 
oxydizement,  forming  the  white,  the  red,  and  the  black 
oxides  of  manganese.  An  oxide  containing  still  more 
oxygen  is  asserted  to  be  of  a  dark  green. 

Metallic  manganese  may  be  obtained,  by  mixing  the 
black  oxide  into  a  ball  with  linseed  oil ;  putting  this  ball 


TANTALIUM. 


151 


into  a  cavity  made  in  a  lump  of  charcoal,  covering  it 
with  a  layer  of  charcoal,  enclosing  the  whole  in  a  cruci¬ 
ble,  and  subjecting  it  to  an  intense  heat  for  one  or  two 
hours.  Saline  fluxes  should  be  rejected  for  reducing 
his  mineral,  because  it  has  so  strong  a  disposition  to 
vitrify,  that  it  would  be  suspended  in  a  flux  of  that  kind. 

Manganese  unites  by  fusion  with  all  the  metals  except 
mercury.  With  copper  and  iron*it  appears  to  combine 
the  most  readily ;  but  none  of  its  alloys  are  used  in  the 
arts,  or  known  to  be  valuable. 

The  sulphuric  acid  attacks  manganese,  and  produces 
hydrogen  gas  ;  the  solution  goes  on  more  slowly  than 
that  of  iron  in  the  same  acid  ;  it  is  colourless.  Sulphuric 
acid  extricates  from  the  oxide  of  manganese,  a  large 
quantity  of  oxygen  gas. 

The  oxide  of  manganese  is  dissolved  by  nitric  acid; 
muriatic  acid,  digested  upon  it,  seizes  its  oxygen,  and 
passes  in  vapour  through  the  water.  This  vapour  is 
oxymuriatic  acid. 

The  oxide  of  manganese  combines  with  the  alkalies. 
It  also  combines  with  sulphur,  which  the  metal  does 
not. 

Manganese  at  a  red  heat  combines  with  phosphorus. 
The  phosphuret  is  of  a  white  colour,  brittle,  granulated, 
disposed  to  crystallize,  not  altered  by  exposure  to  the  air, 
and  more  fusible  than  manganese. 

TANTALIUM. 

From  a  fossil  called  tantalite ,  and  another  called  ytro- 
tantalite,  Ekeberg  extracted  by  means  of  the  fixed 
alkalies,  a  white  powder,  which  he  ascertained  to  be  the 
oxide  of  a  peculiar  metal.  To  this  metal  he  gave  the 
name  of  tantalium. 

When  the  oxide  of  tantalium  above  mentioned  is 
powerfully  heated  with  charcoal,  a  button  of  metal  is 
obtained,  with  a  metallic  lustre  externally,  but  internally 
black  and  without  brilliancy.  Its  hardness  is  7 ;  its 
specific  gravity.  6.5.  The  acids  will  reduce  it  again  tc 


J52 


CHEMISTRY. 


the  state  of  white  oxide,  but  they  will  not  dissolve  it 
The  oxide  is  not  changed  by  a  red  heat.  Caustic  fixed 
alkali  is  the  only  re-agent  which  has  any  action  upon  it. 

TITANIUM. 

Titanium  is  of  a  brownish  red  colour,  almost  Jike  cop¬ 
per.  Its  lustre  is  considerable,  it  is  brittle,  and  very 
difficult  of  fusion.  Its  specific  gravity  is  4.18;  its  hard¬ 
ness  9. 

Titanium  is  obtained  from  a  mineral,  plentiful  in  Hun¬ 
gary,  called  red  schorl,  which  is  its  native  red  oxide  ; 
and  from  another  mineral  obtained  in  Cornwall,  called 
man  acon  ite. 

Vanquelin  obtained  metallic  titanium  from  its  native 
red  oxide,  by  mixing  together  100  parts  of  this  oxide 
with  50  of  calcined  borax,  and  50  of  charcoal,  formed 
into  a  paste  with  oil ;  and  exposed  the  whole  to  the  heat 
of  a  forge  raised  to  1GG°  of  Wedgwood. 

This  metal  is  acted  upon  by  the  principal  acids,  except 
the  nitric,  and  forms  salts  with  them.  It  also  combines 
with  phosphorus.  The  phosphuret  is  of  a  pale  white 
colour,  brittle,  granular,  and  infusible  by  the  blow-pipe 

The  attempts  to  alloy  titanium  have  not  succeeded. 

CHROMIUM. 

Chromium  is  of  a  whitish  colour,  inclining  to  grey  ;  it 
is  very  brittle ;  its  fracture  presents  a  radiated  appear¬ 
ance,  needles  crossing  in  different  directions,  with  inter¬ 
stices  between  them.  It  is  difficult  of  fusion,  resisting  the 
heat  of  the  blow-pipe. 

Chromium  was  discovered  by  Vanquelin,  in  analyzing 
h  beautiful  mineral  called  red  lead  of  Siberia.  The 
mineral  is  a  chromate  of  lead,  in  which  chromium  exists 
in  the  state  of  an  acid.  Its  colour  is  a  fine  aurora  red, 
with  considerable  lustre.  Chromium  has  also  been  found 
United  with  iron,  forming  chromate  of  iron  ;  it  also  exists 
in  some  gems,  of  which  it  appears  to  constitute  the  col 


CHROMIUM. 


153 

ouring  principle.  In  the  emerald  it  exists  in  a  state  of 
green  oxide,  and  the  spiral  ruby  contains  it  in  the  state 
of  an  acid. 

Vanquelin  extracted  this  metal  from  the  red-lead  ore, 
by  adding  to  it  muriatic  acid,  which  combines  with  the 
oxide  of  lead,  and  forms  a  compound  that  is  precipitated, 
the  chromic  acid  remaining  in  solution.  To  abstract  a 
little  muriatic  acid  combined  with  it,  oxide  of  silver  is 
cautiously  added,  and  the  pure  chromic  acid,  being  de¬ 
canted  from  the  precipitate  of  muriate  of  silver,  and 
evaporated,  is  exposed  to  a  very  strong  heat,  excited 
by  a  torge,  in  a  crucible  of  charcoal,  placed  within 
another  of  porcelain.  It  is  thus  reduced  to  the  metallic 
state. 

Sulphuric  acid  decomposes  the  red-lead  ore;  but  it  is 
difficult  to  separate  the  products.  Nitric  acid  does  not 
decompose  this  ore. 

Chromic  acid  is  very  soluble  in  water:  it  is  of  an 
orange-red  colour,  with  a  pungent  metallic  taste.  By 
evaporation,  it  alfords  crystals,  in  long  slender  prisms,  of 
a  ruby-red  colour.  This  acid  combines  with  the  alka¬ 
lies,  earths,  and  metallic  oxides,  and  the  neutral  salts 
which  it  forms  with  them  are  called  chromates. 

The  combinations  of  this  acid  with  metallic  oxides  are 
in  general  possessed  of  very  beautiful  colours,  and  are 
well  adapted  to  the  purposes  of  painting.  That  with 
oxide  of  lead  is  an  orange-yellow,  of  various  shades 
that  with  mercury,  a  vermilion-red;  with  silver,  a  car¬ 
mine-red  ;  with  zinc  and  bismuth,  the  colours  are  yel¬ 
low  ;  with  copper,  cobalt,  and  antimony,  they  are  dull. 

The  term  chromium  is  derived  from  a  Greek  word 
signifying  colour,  and  is  applied  to  this  metal  on  account 
of  the  diversity  of  colours  which  its  compounds  form. 

The  specific  gravity  of  chromium,  and  the  four  follow 
ing  metals,  is  uncertain. 


154 


CHEMISTRY. 


COLUMBIUM. 

A  mineral  in  the  British  Museum,  sent  to  Sir  Ham 
Sloane,  with  some  iron,  from  Massachusetts,  upon  being 
examined  by  Hatchett,  was  found  to  contain  a  new  me¬ 
tallic  substance,  to  which  that  eminent  chemist  has  given 
the  name  of  columbium. 

The  ore  of  columbium  has  never  been  perfectly  re¬ 
duced,  but  it  affords  an  acid,  called  the  columbic  acid, 
which  differs  from  all  other  bodies.  The  alkalies  throw 
it  down  from  its  acid  solutions,  in  white  flakes.  Prussiate 
of  potass  changes  the  blue  colour  to  an  olive  green,  and 
a  precipitate  of  the  same  colour  is  gradually  formed. 
Tincture  of  galls  produces  a  deep  orange  coloured  precip¬ 
itate.  Zinc  occasions  a  white  precipitate.  The  fixed 
alkalies  readily  combine  with  the  columbic  acid.  It  is 
insoluble  and  unalterable  with  regard  to  colour  by  the 
nitric  acid. 


CERIUM. 

Cerium  is  another  newly  discovered  metal,  which 
exists  in  a  mineral  called  cerite.  Ceritc  is  semi-transpa¬ 
rent,  generally  of  a  reddish  colour,  though  occasionally 
yellowish.  Some  specimens  are  hard  enough  to  scratch 
glass,  and  to  strike  fire  with  steel.  To  obtain  the  oxide 
of  cerium,  this  mineral  is  pulverized,  calcined,  and  dissol¬ 
ved  in  nitro-muriatic  acid.  The  filtered  solution,  being 
neutralized  with  potass,  is  to  be  precipitated  by  nitrate 
of  potass,  and  the  precipitate,  well  washed,  and  after¬ 
wards  calcined,  is  oxide  of  cerium.  This  oxide  is 
susceptible  of  two  degrees  of  oxidation  ;  in  the  first  it  is 
white,  and  this  by  calcination  becomes  of  a  fallow  red. 

The  white  oxide  of  cerium,  mixed  with  a  large  pro¬ 
portion  of  borax,  fuses  into  a  transparent  globule;  but 
in  attempts  to  obtain  the  metallic  cerium,  the  quantity 
operated  upon  has  always  been  so  far  dissipated,  that 
the  sensible  properties  of  the  metal  are  unknown. 


OSMIUM. 


155 


IRIDIUM. 

^  Iff  a  black  powder,  left  after  dissolving  crude  platina, 
Tennant  discovered  two  new  metals,  to  one  of  which,  he 
gave  the  name  of  iridium.  To  analyze  this  powder,  it 
was  mixed  with  pure  dry  soda,  and  kept  at  a  red  heat 
for  some  time,  in  a  silver  crucible.  The  alkali  was  then 
separated  by  solution  in  water,  and  the  undissolved  part 
of  the  powder  was  digested  with  muriatic  acid,  with 
which  a  solution,  at  first  of  a  dark  blue,  was  obtained; 
it  afterwards  became  of  a  dusky  olive-green,  and  at  last, 
of  a  deep  red.  'I  his  acid  solution  contains  two  metals, 
but  chiefly  iridium.  By  its  evaporation,  may  be  obtained 
an  imperfectly-crystallized  mass,  which,  dissolved  in  wa¬ 
ter,  gives,  by  evaporation,  distinct  octahedral  crystals. 
These  crystals,  dissolved  in  water,  produce  a  deep  red 
solution,  inclining  to  orange.  By  exposure  to  heat,  the 
acid  may  be  expelled;  but  the  iridium  thus  produced 
has  never  been  fused,  except  by  a  powerful  galvanic 
battery.  Its  oxide,  when  obtained  as  above  stated,  is 
white :  it  neither  combines  with  sulphur  nor  arsenic. 
Lead  unites  with  it  easily,  but  is  separated  by  cupella- 
tion,  leaving  the  iridium  on  the  cupel,  in  the  form  of  a 
coarse  black  powder.  Copper  and  silver  form  with  it 
malleable  alloys;  but  the  iridium  appears  to  be  diflfused 
through  the  silver  only  in  the  state  of  a  fine  powder. 
Gold  remains  malleable,  although  alloyed  with  a  con¬ 
siderable  portion  of  it;  and  is  not  separated  from  it 
either  by  cupellation  or  quartation. 

OSMIUM. 

The  metal  found  along  with  iridium,  in  the  black 
powder  left  after  dissolving  platina,  is  called  osmium. 

The  oxide  of  osmium  may  be  obtained  by  distilling 
with  nitre  the  black  powder  above-mentioned  :  at  a  low 
red  heat,  an  apparently  oily  fluid  sublimes  into  the  neck 
of  the  retort,  which,  on  cooling,  concretes  into  a  solid 
colourless,  semi-transparent  mass.  This,  being  dissolved 


156 


CHEMISTRY. 


in  water,  forms  a  concentrated  solution  of  oxide  of  os¬ 
mium.  This  solution  indelibly  stains  the  skin  of  a  deep 
red  or  black.  Infusion  of  galls  renders  the  solution  at 
first  purple,  but  in  a  little  time,  it  becomes  of  a  deep 
vivid  blue.  If  mercury  be  agitated  with  the  solution,  it 
forms  with  the  osmium  a  perfect  amalgam.  Part  of  the 
mercury  may  be  separated  by  squeezing  it  through 
leather,  and  the  rest  by  distillation,  which  will  leave  the 
osmium  pure,  in  the  state  of  a  black  powder.  This 
powder  has  never  been  fused.  It  forms  malleable  al¬ 
loys  with  copper  and  gold. 

OF  ACIDS. 

Acids  possess  most  or  all  of  the  following  properties 

1.  They  excite  the  sensation  called  sourness  or  acidity 

2.  They  change  the  blue,  green,  and  purple  juices  of 
vegetables  to  red.  3.  They  combine  with  alkalies,  earths 
and  metallic  oxides;  with  which  they  form  compounds 
called  salts.  4.  They  combine  with  water  in  all  pro 
portions. 

Most  of  the  acids  have  been  proved  to  contain  oxygen 
as  a  component  part ;  and  are  more  or  less  strong  in  pro¬ 
portion  as  they  are  combined  with  more  or  less  oxygen 
They  are  not  all,  however,  capable  of  combining  with 
more  than  one  dose  or  proportion  of  oxygen :  a  few  are 
capable  of  combining  with  two  doses  of  oxygen,  and  a 
still  smaller  number  with  three.  No  acid  has  been  ob¬ 
tained  by  itself  in  combination  with  a  fourth  proportion 
of  oxygen.  These  differences  it  becomes  necessary  to 
distinguish ;  and  the  distinction  is  made  in  the  following 
manner. 

When  any  body  contains  the  smallest  portion  of  oxy 
gen,  which  converts  it  into  an  acid,  the  name  of  the  base 
or  radical  of  the  acid  is  terminated  by  ous ;  thus,  we 
have  the  sulphurous  acid.  The  next  degree  of  oxygen- 
isement  is  expressed  by  the  termination  ic ;  thus,  we 
say,  sulphuric  acid.  The  third  degree  is  expressed  by 
the  addition  of  the  word  oxygenized,  or  its  contraction, 


ACETIC  ACID. 


157 


txy ;  thus,  we  have  the  oxymuriatic  acid.  A  fourth  de¬ 
gree  of  oxygenizement  may  be  expressed  by  placing  the 
term  hyper  before  that  of  oxy  ;  thus,  we  have  hyj)er 
oxymuriatic  acid.  There  is  only  one  instance  ot  this 
last  mode  of  expression  being  necessary,  and  that  instance 
only  refers  to  the  acid  as  it  is  supposed  to  exist  in  com¬ 
bination  with  another  body. 

ACERIC  ACID. 

A  peculiar  acid,  said  to  exist  in  the  juice  of  the  ma¬ 
ple.  It  is  decomposed  by  heat,  like  the  other  vegetable 
acids. 

ACETIC  ACID. 

Acetic  acid  may  be  obtained  from  crystallized  acetate 
of  copper,  which  must  be  reduced  to  powder,  and  dis¬ 
tilled.  A  fluid,  possessing  little  acidity,  first  rises,  and 
afterwards,  a  powerful  acid.  This  acid  has  a  greenish 
hue  when  first  prepared,  because  a  small  part  of  the 
oxide  of  copper  comes  over  with  it ;  but  it  may  be  ob¬ 
tained,  perfectly  colourless,  by  distilling  it  with  a  gentle 
heat.  It  may  also  be  prepared,  with  more  certainty  as 
to  its  freedom  from  copper,  by  distilling  acetate  of  soda 
or  acetate  of  potass,  with  half  its  weight  of  sulphuric 
acid. 

Acetic  acid  is  sold  under  the  name  of  radical  vinegar. 
It  is  colourless  like  water :  its  smell  is  extremely  pun¬ 
gent,  and  its  taste  acrid.  When  applied  to  the  skin,  it 
reddens  and  corrodes  it.  It  is  extremely  volatile,  wholly 
evaporating  on  exposure  to  the  air:  and,  when  heated 
in  the  open  air,  it  takes  fire  readily.  At  50°,  it  freezes. 
It  unites  with  water  in  any  proportion ;  and  on  mixture 
with  it,  heat  is  evolved.  It  dissolves  camphor;  and, 
with  the  addition  of  essential  oils,  forms  the  aromatic 
vinegar. 

Acetic  acid  is  used  for  smelling  at;  crystals  of  sulphate 
of  potass  being  put  into  a  bottle,  and  moistened  with  it 
for  that  purpose.  This  mixture  is  called  volatile  salt  of 
14 


158 


CHEMISTRY. 


vinegar.  A  few  drops  of  sulphuric  acid,  added  to  a 
phial  of  the  acetate  of  potass,  make  a  strong  smelling 
bottle  by  the  evolutions  of  the  acetic  acid. 

Acetic  acid  may  be  advantageously  employed  to  sepa¬ 
rate  manganese  from  iron.  When  both  metals  are  dis¬ 
solved  in  this  acid,  and  the  solution  is  evaporated  to  dry¬ 
ness,  the  acid  adheres  to  the  manganese,  but  abandons 
the  iron.  Water  will  then  dissolve  the  acetate  of  man¬ 
ganese  from  the  oxide  of  iron.  Two  or  three  evapora¬ 
tions  and  solutions  are  sufficient  to  remove  the  whole  of 
its  iron. 

Acetic  acid  consists  of  oxygen,  hydrogen,  and  carbon, 
but  the  proportions  of  its  component  parts  have  not  been 
clearly  proved;  with  various  bases,  it  forms  the  salts 
called  acetates. 

BENZOIC  ACID. 

This  acid  is  obtained  from  the  resin  called  benzoin  or 
benjamin ,  which  is  brought  from  the  East  Indies.  By  a 
gentle  heat  the  resin  is  sublimed,  and  condenses  in  the 
form  of  long  needles,  or  straight  filaments  of  a  white 
colour,  crossing  each  other  in  all  directions.  These  are 
what  are  sold  under  the  name  o { foicers  of  benjamin, 
and  consist  of  the  acid  in  question.  When  pure,  they 
are  of  a  brilliant  white,  have  an  aromatic  odour,  are 
entirely  soluble  in  alcohol,  but  the  addition  of  water 
causes  a  precipitate.  Hot  water  dissolves  them  copi¬ 
ously,  but  cold  water  scarcely  at  all.  They  are  not 
altered  by  the  air  ;  their  taste  is  acrid  and  bitter.  They 
form  a  kind  of  paste  if  rubbed  in  a  mortar. 

The  purest  benzoic  acid  may  be  obtained  in  the 
humid  way,  by  boiling  the  resin  with  carbonate  of  soda, 
and  adding  diluted  sulphuric  acid  to  the  filtered  decoc¬ 
tion  as  long  as  it  produces  any  precipitation.  The  pre¬ 
cipitate  is  the  benzoic  acid. 

Benzoic  acid  is  so  inflammable,  that  it  burns  with  a 
clear  yellow  flame,  without  the  assistance  of  a  wick. 

I  he  mineral  acids  dissolve  it,  but  it  separates  from  them 
without  alteration,  by  the  addition  of  water.  It  dissolves 


AIISENIOUS  ACID.  159 

in  oils,  and  melted  tallow.  It  unites  with  earthy  and 
alkaline  bases,  forming  the  salts  called  benzoates. 

AMNIOTIC  ACID. 

A  peculiar  acid  found  in  the  liquor  of  the  amnois  of 
the  cow.  It  exists  in  the  form  of  a  white  pulverulent 
powder.  It  is  slightly  acid  to  the  taste,  but  sensibly 
reddens  vegetable  blues.  It  is  with  difRculty  soluble  in 
cold,  but  readily  soluble  in  boiling  water,  and  in  alcohol. 
When  exposed  to  a  strong  heat,  it  exhales  an  odour  of 
ammonia  and  of  prussic  acid.  iVssisted  by  heat,  it  decom¬ 
poses  carbonate  of  potassa,  soda,  and  ammonia.  It  pro¬ 
duces  no  change  in  the  solutions  of  silver,  lead,  or  mer¬ 
cury,  in  nitric  acid.  Amniotic  acid  may  be  obtained  by 
evaporating  the  liquor  of  the  amnois  of  the  cow  to  a 
fourth  part,  and  suffering  it  to  cool ;  crystals  of  amniotic 
acid  will  be  obtained  in  considerable  quantity.  Whether 
this  acid  exists  in  the  liquor  of  the  amnois  of  other  ani¬ 
mals,  is  not  yet  known. 

ARSENIOUS  ACID. 

This  is  nothing  more  than  the  white  oxide  of  arsenic 
sold  from  the  stores,  without  any  preparation.  It  has  a 
weakly  acid  taste,  and  sensibly  reddens  the  tincture  ot 
cabbage  and  litmus,  an^  most  other  vegetable  blues;  the 
syrup  of  violets,  which  it  turns- green,  is  an  exception. 
If  thrown  on  burning  coals,  or  a  red-hot  iron,  it  is  vola¬ 
tilized  in  the  form  of  a  white  vapour,  which  emits  tne 
smell  of  garlic.  By  a  strong  heat  it  is  vitrified  into  a 
transparent  glass.  It  only  contains  about  seven  per  cent. 

°f  ArJemoiis  acid  is  soluble  in  15  times  its  weight  of  boil¬ 
ing  water,  but  requires  for  its  solution  eighty  times  1  s 
weight  of  cold  water.  The  solution  crystallizes  best  by 
slow  evaporation  ;  it  is  very  acrid  ;  it  unites  with  the 
e»vthy  bases,  decomposes  the  alkaline  sulphurets,  and 
forms  with  them  a  yellow  precipitate,  in  which  the 
orsenic  approaches  to  the  metallic  state. 


160 


CHEMISTRY. 


The  combinations  of  arsenious  acid  with  different  bases 

re  called  arsenites. 

BORACIC  ACID. 

Boracic  acid  is  procured  from  the  salt  called  borax,  in 
ihe  following  manner:  the  borax  is  dissolved  in  hot 
water,  and  the  solution  filtered;  sulphuric  acid  is  added 
very  gradually  to  the  solution,  till  it  has  a  sensibly  acid 
taste  ;  being  then  left  to  cool,  a  number  of  small,  shining 
laminated  crystals  form  in  it ;  these  crystals  are  th 
boracic  acid ;  they  are  to  be  washed  with  cold  water, 
and  dried  upon  brown  paper. 

The  crystals  of  boracic  acid  are  thin  irregular  hexa¬ 
gons,  of  a  silvery  whiteness.  They  are  soft  and  unctuous 
to  the  touch,  almost  like  spermaceti.  They  have  no 
smell,  but  a  bitterish  taste,  with  a  slight  degree  of  acidity  ; 
and  they  are  unalterable  in  the  air.  When  mixed  with 
spirit  of  wine,  they  cause  it  to  burn  with  a  green  flame. 
When  sulphuric  acid  is  poured  upon  them,  a  transient 
odour  of  musk  is  perceived. 

Boracic  acid,  when  exposed  to  a  violent  fire,  is  converted 
into  a  transparent  glass ;  this  glass  is  soluble  in  water, 
and  the  acid  is  again  produced  from  evaporation. 

It  is  much  employed  in  analyzing  minerals,  as  it  brings 
almost  all  the  stones  into  solution. 

BUTYRIC  ACID. 

WrE  owe  the  discovery  of  this  acid  to  M.  Chevreul. 
Butter,  he  says,  is  composed  ot  two  fat  bodies,  analogous 
to  those  of  hogs’  lard,  of  a  colouring  principle,  and  a 
remarkably  odorous  one,  to  which  it  owes  the  properties 
that  distinguish  it  from  the  fats,  properly  so  called.  This 
principle,  which  he  has  called  butyric  acid,  forms  well 
characterized  salts  with  barytes,  strontian,  lime,  the 
oxides  ot  copper,  lead,  &c. ;  100  parts  of  it  neutralize 
u  quantity  ol  base  which  contains  10  of  oxygen.  M. 
Chevreul  has  not  explained  his  method  of  separating 
this  acid  from  the  other  constituents  of  butter. 


CAMPHORIC  ACID,  CARBONIC  ACID.  161 

CAMPHORIC  ACID. 

Camphor  is  a  concrete  essential  oil,  of  a  strong  taste 
and  smell ;  it  is  extracted  by  sublimation  from  a  species 
of  laurel  in  the  East  Indies,  and  has  a  crystalline  form. 
It  is  so  volatile,  that  it  cannot  be  melted  in  open  vessels, 
and  so  imflammable,  that  it  burns  even  on  the  surface  of 
water.  Kosegarten,  by  distilling  nitric  acid  eight  times 
successively  from  this  substance,  obtained  an  acid  in 
crystals,  which  is  called  camphoric  acid. 

Camphoric  acid  is  in  snow-white  crystals,  which  efflo¬ 
resce  in  the  air.  It  has  a  slightly  acid,  bitter  taste,  and 
a  smell  like  saffron.  It  reddens  vegetable  blues.  It  re¬ 
quires  200  times  its  weight  of  cold  water  to  dissolve  it ; 
but  boiling  water  takes  up  one-twelfth.  If  thrown  upon 
burning  coals,  it  is  entirely  dissipated  in  a  thick  aromatic 
smoke.  With  a  gentle  heat  it  melts  and  is  sublimed. 
It  is  soluble  in  alcohol,  and  not  precipitated  from  it  by 
the  addition  of  water,  a  property  which  distinguishes  it 
from  the  benzoic  acid.  It  does  hot  precipitate  lime  from 
lime-water. 

The  mineral  acids  dissolve  camphoric  acid  entirely,  it 
is  also  dissolved  by  the  fixed  and  volatile  oils.  It  unites 
readily  with  the  earths  and  alkalies,  forming  the  salts 
called  camphorates. 

CARBONIC  ACID. 

Carbonic  acid  gas  is  the  result  of  the  combustion  of 
carbon.  Every  100  parts  of  it,  according  to  Tennant, 
contain  18  parts  of  carbon  and  82  of  oxygen.  Its 
weight  is  to  atmospheric  air  as  1500  to  1000.  "It  has  no 
smell ;  is  invisible  and  elastic,  like  common  air,  but 
extinguishes  flame,  and  is  totally  unfit  for  respiration. 

Carbonic  acid  is  contained  in  the  air  to  the  amount  of 
about  one  part  in  the  thousand.  It  is  absorbed  by  water 
if  agitated,  or  long  in  contact  with  it.  Strong  pressure 
will  cause  the  water  to  absorb  three  times  its  bulk  of 
this  gas,  which  imparts  to  it  a  taste  agreeably  acidulous 
14*  L 


162 


CHEMISTRY. 


and  causes  it  to  have  a  sparkling  lustre  when  poured 
from  one  vessel  to  another.  The  Pyrmont,  Spa,  and 
Seltzer  waters,  arc  neutral  combinations  of  carbonic 
acid  with  water,  and  they  can  be  imitated  by  art  with 
the  greatest  precision. 

The  specific  gravity  of  water  saturated  with  carbonic 
acid  is  1.0015.  If  water  containing  carbonic  acid  be 
frozen,  the  whole  of  this  gas  separates  in  freezing,  and, 
therefore,  ice  is  never  found  to  contain  any.  A  boiling 
heat  also  produces  this  separation. 

Carbonic  acid,  from  its  gravity,  may  be  poured  from 
one  vessel  to  another,  but  if  a  portion  of  it  be  left  in  an 
open  vessel,  for  any  length  of  time,  it  will  be  found  to 
have  escaped  ;  the  air  having  an  attraction  for  it,  gradu¬ 
ally  absorbs  it,  and  will  even  abstract  it  from  water. 

Carbonic  acid  exists  In  incalculable  quantities,  com¬ 
bined  with  other  substances.  Marble,  limestone,  and 
chalk  consist  of  it  in  combination  with  lime:  it  forms 
about  one-third  of  their  weight,  and  may  be  disengaged 
from  any  of  these  substances,  by  means  of  an  acid,  or 
considerable  heat.  The  former  means  is  generally  more 
convenient,  when  a  quantity  is  required  for  the  purpose 
of  experiment.  The  sulphuric  acid,  diluted  with  about 
six  times  its  weight  of  water,  is  poured  upon  the  marble, 
chalk,  or  limestone,  previously  reduced  to  a  powder.  An 
effervescence  immediately  ensues :  this  is  occasioned  by 
the  extrication  of  carbonic  acid  gas,  which  must  be  col¬ 
lected  by  means  of  the  pneumatic  apparatus.  The  mer¬ 
curial  trough  should  be  used,  if  the  gas  is  not  intended 
for  immediate  use. 

Alcohol,  and  spirit  of  turpentine,  absorb  double  their 
weight  of  carbonic  acid  gas;  olive  oil,  its  own  bulk. 
Ether  mixes  with  it  in  the  state  of  gas. 

Carbonic  acid  enters  into  combination  with  alkalies, 
alkaline  earths,  alumine,  zircon,  and  metallic  oxides, 
with  which  it  forms  salts  called  carbonates. 

Water,  impregnated  with  carbonic  acid,  and  applied 
to  the  roots  of  plants,  is  highly  favourable  to  vegetation ; 
but,  if  this  gas  be  applied  to  the  leaves,  as  an  atmo¬ 
sphere,  it  is  injurious. 


CASE1C  ACID,  CHLORIC  ACID. 


163 


CASEIC  ACID. 

The  name  given  by  Proust  to  an  acid  formed  ir 
cheeses,  to  which  he  ascribes  their  flavour. 

CHLORIC  ACID. 

This  acid  was  first  eliminated  from  salts  contain 
mg  it  by  Gay  Lussac,  and  described  by  him,  in  his  ad 
mirable  memoir  on  iodine.  When  a  current  of  chlorine 
is  passed  for  some  time  through  a  solution  of  barytic 
earth,  in  warm  water,  a  substance  called  hyper-oxy- 
muriate  of  barytes,  by  its  first  discoverer,  Chenevix,  is 
formed,  as  well  as  some  common  muriate.  The  latter 
is  separated,  by  boiling  phosphate  of  silver  in  the  com¬ 
pound  solution.  The  former  may  then  be  obtained  by 
evaporation,  in  fine  rhomboidal  prisms.  Into  a  diluted 
solution  of  this  salt,  Gay  Lussac  poured  weak  sulphuric 
acid.  Though  he  added  only  a  few  drops  of  acid,  not 
nearly  enough  to  saturate  the  barytes,  the  liquid  became 
sensibly  acid,  and  not  a  bubble  of  oxygen  escaped.  By 
continuing  to  add  sulphuric  acid  with  caution,  he  suc¬ 
ceeded  in  obtaining  an  acid  liquid,  entirely  free  from 
sulphuric  acid  and  barytes,  and  not  precipitating  nitrate 
of  silver.  It  was  chloric  acid  dissolved  in  water. 

This  acid  has  no  sensible  smell.  Its  solution  in  water 
is  perfectly  colourless.  Its  taste  is  very  acid,  and  it  red¬ 
dens  litmus  without  destroying  the  colour.  It  produces 
no  alteration  on  solution  of  indigo  in  sulphuric  acid.  Light 
does  not  decompose  it.  It  may  be  concentrated  by  a 
gentle  heat,  without  undergoing  decomposition,  or  with¬ 
out  evaporating.  It  was  kept  a  long  time  exposed  to  the 
air  without  sensible  diminution  of  its  quantity.  When 
concentrated  it  has  something  of  an  oily  consistency. 
When  exposed  to  heat,  it  is  partly  decomposed  into 
oxygen  and  chlorine,  and  partly  volatilized  without 
alteration.  Muriatic  acid  decomposes  it  in  the  same 
way,  at  the  common  temperature.  Sulphurous  acid,  and 
sulphuretted  hydrogen,  have  the  same  property ;  but 


CHEMISTRY. 


164 

nitric  acid  produces  no  change  upon  it.  Combined  with 
ammonia,  it  forms  a  fulminating  salt.  It  does  not  pre¬ 
cipitate  any  metallic  solution.  It  readily  dissolves  zinc, 
disengaging  hydrogen  ;  but  it  acts  slowly  on  mercury.  It 
cannot  be  obtained  in  the  gaseous  state.  Its  taste  is  not 
only  acid  but  astringent,  and  its  colour,  when  concentra¬ 
ted,  is  somewhat  pungent. 

Chloric  acid  combines  with  the  bases,  and  forms  the 
chlorates,  a  set  of  salts  formerly  known  by  the  name  of 
h yp e r-oxyge natecl  muriates. 

CHLORIODIC  ACID. 

Sir  H.  Davy  formed  it,  by  admitting  chlorine  in  excess 
to  known  quantities  of  iodine,  in  vessels  exhausted  of  air, 
and  repeatedly  heating  the  sublimate.  Operating  in  this 
way,  he  found  that  iodine  absorbs  less  than  one-third  of 
its  weight  of  chlorine. 

Chloriodic  acid,  a  very  volatile  substance,  formed  by 
the  sublimation  of  iodine  in  a  great  excess  of  chlorine, 
is  of  a  bright  yellow  colour ;  when  fused  it  becomes  of  a 
deep  orange,  and  when  rendered  clastic,  it  forms  a  deep 
orange  coloured  gas.  It  is  capable  of  combining  with 
much  iodine  when  they  are  heated  together;  its  colour 
becomes,  in  consequence,  deeper,  and  the  chloriodic  acid 
and  the  iodine  rise  together  in  the  elastic  state.  The 
solution  of  the  chloriodic  acid  in  water,  likewise  dissolves 
large  quantities  of  iodine,  so  that  it  is  possible  to  obtain 
a  fluid  containing  very  diflferent  proportions  of  iodine  and 
chlorine. 

When  two  bodies  so  similar  in  their  characters,  and  in 
the  compounds  they  form,  as  iodine  and  chlorine,  act 
upon  substances  at  the  same  time,  it  is  difficult,  Sir  II. 
Davy  observes,  to  form  a  judgment  of  the  diflTerent  parts 
they  play  in  the  new  chemical  arrangement  produced. 
It  appears  most  probable,  that  the  acid  property  of  the 
chloriodic  compound  depends  upon  the  combination  of  the 
two  bodies;  and  its  action  upon  solutions  of  the  alkalies 
and  the  earths  may  be  easily  explained,  when  it  is  con- 


CHROMIC  ACID,  CITRIC  ACID.  165 

sidered  that  chlorine  has  a  greater  tendency  than  iodine 
to  form  double  compounds  with  the  metals,  that  iodine 
has  a  greater  tendency  than  chlorine  to  form  triple 
compounds  with  oxygen  and  the  metals. 

A  triple  compound  of  this  kind  with  sodium  may  exist 
in  sea-water,  and  would  be  separated  with  the  first  crys-. 
tals  that  are  formed  by  its  evaporation.  Hence,  it  may 
exist  in  common  salt.  "Sir  H.  Davy  ascertained  by  feeding 
birds  with  bread  soaked  with  water,  holding  some  of  it 
in  solution,  that  it  is  not  poisonous  like  iodine  itself. 

CHROMIC  ACID. 

This  acid  is  furnished  by  the  mineral  called  the  red 
lead  ore  of  Siberia,  which  is  a  chromate  of  lead,  and 
from  which  chromium  is  obtained.  It  also  exists  in  the 
chromate  of  iron,  which  is  more  common  than  the  former 
mineral,  and  in  France  is  even  abundant. 

The  acid  is  extracted  from  the  real  lead  ore  of  Siberia, 
by  boiling  100  parts  of  this  mineral,  with  300  of  carbo¬ 
nate  of  potass,  and  400  of  water,  and  separating  the 
alkali  by  means  of  weak  nitric  acid.  It  is  an  orange 
coloured  powder,  which  has  an  acrid,  metallic  taste,  is 
soluble  in  water,  and  crystallizable.  If  exposed  to  the 
action  of  light  and  heat,  this  powder  loses  oxygen  and 
its  acid  properties,  and  is  converted  into  the  green  oxide 
of  chromium. 

If  the  muriatic  acid  be  distilled  upon  the  chromic  acid, 
it  is  oxygenized,  and  if  simply  mixed  with  the  chromic 
acid,  the  same  effect  takes  place,  for  it  acquires  the 
property  of  dissolving  gold.  This  arises  from  the  readi¬ 
ness  with  which  chromic  acid  parts  with  its  oxygen. 

Chromic  acid  unites  readily  with  alkalies.  It  also 
unites  with  borax,  glass,  and  phosphoric  acid,  to  which 

it  communicates  an  emerald  green  colour. 

u  / 

CITRIC  ACID. 

The  citric  acid  is  found  in  the  juice  of  lemons,  oranges, 
unripe  grapes,  and  some  other  fruits.  It  is  extremely 


166 


CHEMISTRY. 


acid  to  the  taste,  crystallizablc,  and  very  soluble  in 
water :  cold  water  dissolves  rather  more  than  its  own 
weight  of  it,  and  hot  water  double  its  weight.  The 
solution  undergoes  a  spontaneous  decomposition  by  long 
keeping. 

If  lemon  juice  be  exposed  in  an  open  vessel,  it  deposits 
a  quantity  of  mucilage,  from  which  it  may  be  separated 
by  decantation  and  Alteration.  If  the  juice  thus  purified, 
be  exposed  to  a  freezing  temperature,  and  the  ice  formed 
in  it,  which  consists  only  of  its  aqueous  particles,  be  re¬ 
moved  as  it  is  formed,  the  lemon  juice  will  be  obtained 
in  a  state  of  high  concentration.  Its  quantity  will  be 
only  about  one-eighth  of  what  it  was  at  first,  but  its 
strength  will  be  eight  times  greater.  It  may  be  kept  for 
use,  or  may  be  made  into  dry  lemonade,  by  adding  six 
times  its  weight  of  fine  loaf-sugar  in  powder. 

The  lemon  juice,  prepared  as  above,  is  not  pure  citric 
acid,  but  it  retains  a  flavour  which  renders  it  better  for 
domestic  use  than  if  it  were  pure.  To  prepare  pure 
citric  acid,  Scheele  saturated  lemon-juice  with  lime, 
edulcorated  the  precipitate,  which  consisted  of  citric 
acid  and  lime,  separated  the  lime  from  it  bv  diluted 
sulphuric  acid,  cleared  it  from  the  sulphate  of  lime  bv 
repeated  Alterations  and  evaporations;  then  evaporated 
it  to  the  consistence  of  a  syrup,  and  set  it  in  a  cool  place: 
a  quantity  of  crystals  formed  which  were  pure  citric  acid. 
Tike  the  oxalic  acid,  it  possesses  the  property  of  speedily 
dissolving  the  oxides  of  iron.  The  dyers  make  use  of  it, 
for  no  other  acid  can  be  employed  with  so  much  success 
in  enlivening  the  colours  given  by  saffron :  it  appears 
also  that  it  will  form  with  granitin,  a  liquor  which  with 
cochineal,  produces  a  scarlet  colour  superior  to  the  usual 
dye,  especially  with  silk  and  morocco  leather.  Citric 
ac  id  whitens  and  hardens  tallow,  but  as  tartaric  acid  acts 
nearly  as  well  in  this  respect,  and  is  considerably  cheap¬ 
er,  it  is  seldom  made  use  of  for  this  purpose. 

Citric  acid  oxidizes  iron,  zinc,  and  tin.  It  does  notact 
upon  gold,  silver,  platina,  mercury,  bismuth,  antimony 
or  arsenic. 


COLUMBIC  ACID,  DELPHINIC  ACID. 


1G7 


The  combinations  of  the  citric  acid  with  the  different 
bases,  are  called  citrates. 


COLUMBIC  ACID 

The  experiments  of  Hatchett  have  proved  that  a  pe 
culiar  mineral,  found  in  Massachusetts,  deposited  in  the 
British  Museum,  consisted  of  one  part  of  oxide  of  iron 
and  somewhat  more  than  three  of  a  white  coloured  sub¬ 
stance,  possessing  the  properties  of  an  acid.  Its  basis 
was  metallic.  Hence,  he  named  this  columbium,  and 
the  acid,  the  columbic.  Dr.  Wollaston,  by  very  exact 
analytical  comparisons,  proved  that  the  acid  of  Hatchett 

Iwas  the  oxide  of  the  metal  lately  discovered  in  Sweden 
by  Ekeberg,  in  the  mineral  ytrotantalite,  and  thence 
called  tantalum.  Dr.  Wollaston’s  method  of  separating 

(the  acid  from  the  mineral  is  peculiarly  elegant.  One 
part  of  tantalite,  live  parts  of  carbonate  of  potassa,  and 
two  parts  of  borax,  are  fused  together  in  a  platina  cru¬ 
cible.  The  mass,  after  being  softened  in  water,  is  acted 
on  by  muriatic  acid.  The  iron  and  manganese  dissolve, 
while  the  columbic  acid  remains  at  the  bottom.  It  is  in 
the  form  of  a  white  powder,  which  is  insoluble  in  nitric 
and  sulphuric  acids,  but  partially  in  muriatic.  It  forms, 
with  barytes,  an  insoluble  salt,  of  which  the  proportions, 
according  to  Berzelius,  are  24.4  acid,  and  9.70  barytes. 
By  oxidizing  a  portion  of  the  tantalum  or  columbium, 
Berzelius  concludes  the  composition  of  the  acid  to  be 
100  metal,  and  5.485  oxygen. 

DELPHINIC  ACID. 

The  name  of  an  acid  extracted  from  the  oil  of  the  dol¬ 
phin.  It  resembles  a  volatile  oil ;  has  a  light  lemon 
colour,  and  a  strong  aromatic  odour,  analogous  to  that 
of  rancid  butter.  Its  taste  is  pungent,  and  its  vapour  has 
a  sweetened  taste  of  ether.  It  is  slightly  soluble  in 
water,  and  very  soluble  in  alcohol.  The  latter  solution 
strongly  reddens  litmus.  100  parts  of  delphinic  acid 


168 


CHEMISTRY. 


neutralize  a  quantity  of  base  which  contains  9  of  oxy 
gen;  whence,  its  prime  equivalent  appears  to  be  11.11. 

ELLAGIC  ACID. 

So  named  by  Braconnet,  by  reversing  the  word  galle. 
The  deposit,  which  forms  in  infusion  of  nut-galls  left  to 
itself,  is  not  composed  solely  of  gallic  acid,  and  a  matter 
which  colours  it.  It  contains,  beside  a  little  gallate  and 
sulphate  of  lime,  and  a  new  acid,  which  was  pointed  out 
by  Chevreuil,  in  1815.  an  acid  on  which  Braconnet  made 
observations  in  1818,  and  which  he  proposed  to  call  acid 
ellagic,  from  the  word  galle,  reversed.  Probably  thir 
acid  does  not  exist  ready  formed  in  nut-galls.  It  is  in 
soluble;  and,  carrying  down  with  it  the  greater  part  of 
the  gallic  acid,  forms  the  yellowish  crystalline  deposit 
But  boiling  water  removes  the  gallic  acid  from  the  ella 
gic ;  whence,  the  means  of  separating  them  one  from 
another. 

It  has  a  pale  yellow  lemon  colour,  but  no  smell.  Heat 
and  light  decompose  it.  Hydroeganic  acid  is  then  formed, 
and  white  ferro-prussiate  of  iron,  which  soon  becomes 
blue.  Its  affinity  for  the  bases  enables  it  to  displace  acetic 
acid,  without  heat,  from  the  acetates^  and  to  form  ferro- 
prussiates. 

FLUORIC  ACID. 

This  acid  is  contained  in  the  mineral  called  Jluor  or 
fusible  spar,  which  consists  of  fluoric  acid  and  lime.  If 
sulphuric  acid  be  poured  upon  this  spar  in  powder,  the 
lime  combines  with  it  to  form  sulphate  of  lime,  and  the 
fluoric  acid  is  expelled,  and  they  may  be  collected  by  the 
pneumatic  apparatus.  The  sulphuric  acid  should  be 
well  concentrated,  and  equal  in  weight  to  the  fluor  spar. 
A  leaden  retort  must  be  used  in  the  distillation,  and 
only  a  gentle  heat  will  be  required.  The  gas  should  be 
eceived  over  mercury. 

Fluoric  acid  gas  is  invisible  and  elastic  like  common 
air;  it  will  not  maintain  combustion,  and  cannot  be 


FLUORIC  ACID. 


169 

breathed  without  causing  death.  It  has  the  odour  of 
muriatic  acid,  but  is  more  corrosive,  and  when  exposed 
to  a  moist  atmosphere,  it  becomes  cloud)^. 

!  luoric  acid  gas  is  heavier  than  common  air.  It  cor¬ 
rodes  the  -skin  almost  instantly.  It  combines  rapidly 
with  water,  with  which  it  forms  liquid  fluoric  acid;  as  it 
dissolves  silex,  it  cannot  be  prepared  in  glass  vessels,  nor 
kept  in  them,  unless  they  be  lined  internally  with  wax 
or  some  similar  coating.  The  acid  combines  with  the 
silex  of  glass,  and  the  silex  passes  over  with  it  in  the 
distillation.  It  is  for  this  reason  that  it  is  usually  kept 
as  well  as  prepared  in  leaden  or  tin  bottles.  It  is  absorb¬ 
ed  by  alcohol  and  ether  without  altering  their  qualities : 
water  impregnated  with  it  must  be  cooled  down  to  23° 
before  it  will  freeze. 

The  action  of  fluoric  acid,  upon  all  inflammable  sub¬ 
stances,  is,  in  general,  very  feeble. 

It  will  oxidize  iron,  zinc,  copper,  and  arsenic;  but 
has  no  action  upon  platina,  gold,  silver,  lead,  tin,  anti¬ 
mony,  cobalt,  mercury. 

It  combines  with  alkalies,  alkaline  earths,  alumine, 
and  metallic  oxides;  and  forms  the  salts  catted Jluatcs. 

Fluoric  acid  has  been  discovered  in  the  enamel  of 
the  human  teeth,  and  in  ivory.  VaHKguelin  also  found  it 
in  topaz. 

1  he  only  use  to  which  fluoric  acid  Fas  been  applied, 
is  that  of  etching  upon  glass.  For  this  purpose,  either 
the  liquid  fluoric  acid  may  be  employed,  or  the  gas.  If 
the  former,  the  glass  remains  polished  where  the  acid 
has  corroded  ;  but  with  the  gas,  the  lines  have  the  ap¬ 
pearance  as  if  the  glass  had  been  ground,  and  not  polished. 
Landscapes,  and  other  designs,  properly  executed  upon 
glass,  by  means  of  this  acid,  have  an  elegant  appear 
ance.  The  process  is  the  same  as  that  for  etching  upon 
copper,  except  that  so  much  care  is  not  necessary  in  pre 
paring  the  ground  :  bees’-wax  alone  will  suflice. 


15. 


170 


CHEMISTRY. 


GALLIC  ACID. 

This  acid  is  found  in  the  nut-galls,  and  generally,  ir 
all  astringent  vegetables,  though  it  exists  independently 
of  the  astringent  principle.  The  nut-gall  is  an  excres¬ 
cence  produced  on  a  species  of  oak,  by  the  puncture  of 
an  insect. 

The  gallic  acid  may  be  obtained  by  various  processes  t 
the  following  method  is  proposed  by  Proust.  Pour  a 
solution  of  the  muriate  of  tin  into  an  infusion  of  nut-galls 
a  copious  yellow  precipitate  is  instantly  formed,  consist¬ 
ing  of  the  tanning  principle,  combined  with  the  oxide  of 
tin.  After  diluting  the  liquor  with  a  sufficient  quantity 
of  water  to  separate  any  portion  of  this  precipitate  which 
the  acids  might  hold  in  solution,  the  precipitate  is  to  be 
separated  by  Alteration.  The  liquid  contains  gallic  acid, 
muriatic  acid,  and  muriate  of  tin.  To  separate  the  tin, 
a  quantity  of  the  sulphuretted  hydrogen  gas  is  to  be 
mixed  with  the  liquid.  Sulphuret  of  oxide  of  tin  is  pre¬ 
cipitated  under  the  form  of  a  brown  powder.  The  liquid 
is  then  to  be  exposed  for  some  days  to  the  light,  covered 
with  paper,  till  the  superfluous  sulphuretted  hydrogen 
gas  exhales.  After  this,  it  is  to  be  evaporated  to  the 
proper  degree  of  concentration,  and  left  to  cool.  Crys¬ 
tals  of  gallic  acid  are  deposited  :  these  are  to  be  sepa¬ 
rated  by  Alteration,  and  washed  with  cold  water.  The 
evaporation  of  the  rest  of  the  liquid  is  to  be  repeated,  till 
all  the  gallic  acid  is  obtained  from  it. 

The  gallic  acid  thus  obtained  has  a  very  acid  taste ; 
it  reddens  vegetable  blues,  dissolves  in  1^  parts  of  boil¬ 
ing  water,  and  12  parts  of  cold  water.  Alcohol  dissolves 
one-fourth  of  its  weight  in  the  cold,  and  its  own  weight, 
if  assisted  by  heat. 

Gallic  acid  thrown  upon  burning  coals,  inflames,  and 
emits  an  aromatic  odour,  not  very  dissimilar  to  that  of 
the  benzoic  acid.  Its  residuum  is  charcoal.  It  is  decom¬ 
posed  by  distillation.  It  has  a  great  affinity  for  most  of 
the  metallic  oxides,  which  it  will  take  from  thp  strongest 
acids.  A  solution  of  gold  it  renders  green,  and  causes  a 


HYDRIODIC  ACID,  IODJC  ACID.  17  1 

Drown  precipitate,  which  readily  passes  to  the  metallic 
state.  On  the  nitric  solution  of  silver,  it  has  the  same 
effect.  Mercury,  it  precipitates  of  an  orange-yellow; 
copper,  brown  ;  bismuth,  of  a  lemon  colour;  lead,  white  ; 
iron,  purple,  or  black  ;  for  which  reason,  nut-galls  arc 
used  to  form  writing-ink :  they  are  also  extensively  used 
in  dyeing.  Piatina,  zinc,  tin,  cobalt,  and  manganese,  it 
does  not  precipitate. 

The  combination  of  the  gallic  acid  with  the  different 
bases,  are  called  gallates. 

HYDRIODIC  ACID. 

A  gaseous  acid  in  its  insulated  state.  If  4  parts  of 
iodine  be  mixed  with  one  of  phosphorus,  in  a  small  glass 
retort,  applying  a  gentle  heat,  and  adding  a  few  drops  of 
water  from  time  to  time,  a  gas  comes  over,  which  must 
be  received  in  the  mercurial  bath.  It  is  elastic  and 
invisible,  but  has  a  smell  somewhat  similar  to  that  of 
muriatic  acid.  Mercury  after  some  time  decomposes  it, 
seizing  its  iodine,  and  leaving  its  hydrogen,  equal  to  one 
half  the  original  bulk,  at  liberty.  Chlorine,  on  the  other 
hand,  unites  to  its  hydrogen,  and  precipitates  the  iodine. 
From  these  experiments,  it  evidently  consists  of  vapour 
of  iodine  and  hydrogen,  which  combine  in  equal  volumes, 
without  change  of  their  primitive  bulk.  Hydriodic  acid 
is  partly  decomposed  at  a  red  heat,  and  the  decomposition 
is  complete  if  it  be  mixed  with  oxygen.  Water  is  form¬ 
ed  and  iodine  separated. 

IODIC  ACID. 

When  barytes  water  is  made  to  act  on  iodine,  a 
soluble  hydriodate,  and  an  insoluble  iodate  of  barytes, 
are  formed.  On  the  latter  well  washed,  pour  sulphuric 
acid  equivalent  to  the  barytes  present,  diluted  with  twice 
its  weight  of  water,  and  hfcat  the  mixture.  The  iodic 
acid  quickly  abandons  a  portion  ot  its  base,  and  com¬ 
bines  with  the  water;  but  though  even  less  than  the 


CHEMISTRY. 


172 

equivalent  proportion  of  sulphuric  acid  has  been  used,  a 
little  of  it  will  be  found  mixed  with  the  liquid  acid.  11 
we  endeavour  to  separate  this  portion,  by  adding  baiytes 
water,  the  two  acids  precipitate  together. 


LACCIC  ACID. 

This  acid  is  obtained  from  lacca,  the  substance  m 
which  it  exists.  Dr.  Sohn  made  a  watery  extract  of 
powdered  sticklac,  and  evaporated  it  to  dryness,  lie 
digested  alcohol  on  this  extract,  and  evaporated  the  alco¬ 
holic  extract  to  dryness.  He  then  digested  this  mass  in 
ether,  and  evaporated  the  ethereal  solution  ;  when  he 
obtained  a  syrup  mass  of  a  light  yellow  colour,  which 
was  again  dissolved  in  alcohol.  On  adding  water  to  this 
solution,  a  little  resin  fell.  A  peculiar  acid  united  to 
potassa  and  lime  remains  in  the  solution,  which  is  ob¬ 
tained  free,  by  forming  with  acetate  of  lead  an  insoluble 
laccate,  and  decomposing  this  with  the  equivalent  quan¬ 
tity  of  sulphuric  acid.  Laccic  acid  crystallizes;  it  lias  a 
wine  yellow  colour,  a  sour  taste,  and  is  soluble  as  we 
have  seen,  in  water,  alcohol,- and  ether.  It  precipitates 
lead  and  mercury  white,  but  it  does  not  affect  lime, 
barytes,  or  silver  in  their  solutions.  It  throws  down  the 
salts  of  iron  white.  With  lime,  potassa,  or  soda,  it  forms 
deliquescent  salts,  soluble  in  alcohol. 

LACTIC  ACID. 

This  is  the  acid  which  appears  in  milk,  that  has  be¬ 
come  sour.  To  obtain  it  by  Scheelc’s  process,  evaporate 
a  quantity  of  sour  whey  to  an  eighth  part,  and  then  filter 
it;  this  separates  the  cheesy  part.  Saturate  the  liquid 
with  lime-water,  and  the  phosphate  of  lime  precipitates. 
Filter  again,  and  dilute  the  liquid  with  three  times  its 
own  bulk  of  water;  add  to  it  oxalic  acid,  drop  by  drop, 
to  precipitate  the  lime  which  has  dissolved  from  the  lime- 
water;  then  add  a  very  small  quantity  of  lime-water,  to 
see  whether  loo  much  oxalic  acid  has  been  added.  If 


LITHIC  Oil  URIC  ACID,  MALIC  ACID.  173 

there  has,  oxalate  of  lime  immediately  precipitates. 
Evaporate  the  solution  to  the  consistence  of  honey,  pour 
in  a  sufficient  quantity  of  alcohol,  and  filter  again ;  the 
acid  passes  through  dissolved  in  the  alcohol,  but  the 
sugar  of  milk,  and  every  other  substance,  remains  behind. 
Add  to  the  solution  a  small  quantity  of  water,  and  distil 
with  a  low  heat;  the  alcohol  passes  over,  and  leaves 
jehind  the  lactic  acid  dissolved  in  water. 

Lactic  acid  is  incapable  of  crystallizing ;  when  evapo¬ 
rated  to  dryness,  it  deliquesces  in  the  air.  Its  salts  are 
called  lactates. 

LITHIC  OR  URIC  ACID. 

Scheele,  in  analyzing  human  calculi,  found  that  a 
peculiar  acid  constituted  a  greater  part  of  them  all,  and 
nearly  the  whole  of  some.  It  exists  in  human  urine, 
from  which  it  spontaneously  separates  in  a  few  days  in 
the  form  of  red  crystals  with  brilliant  facets,  the  urine 
at  the  same  time  losing  its  colour  and  acid  nature.  It 
has  neither"  taste  nor  smell,  but  reddens  vegetable  blues. 
It  is  soluble  in  2000  times  its  weight  of  cold  water.  It 
is  a  composition  of  carbon,  nitrogen,  hydrogen,  and 
oxygen. 

This  acid  is  found  in  the  urine  of  the  camel,  and  in 
fiiose  anthritic  concretions  commonly  called  chalk-stones. 

MALIC  ACID. 

This  acid  is  obtained  by  saturating  the  juice  of  apples 
with  alkali,  pouring  in  the  acetous  solution  of  lead, 
antil  it  occasions  no  more  precipitate.  The  precipitate 
s  then  to  be  edulcorated,  and  sulphuric  acid  poured  on 
it,  until  the  liquor  has  acquired  a  fresh  acid  taste,  with¬ 
out  any  mixture  of  sweetness.  The  whole  is  then  to  be 
filtered,  to  separate  the  sulphate  of  lead.  The  filtered 
liquor  is  the  malic  acid,  which  is  very  pure,  remains 
always  in  a  fluid  state,  and  cannot  be  rendered  concrete. 

1 5  * 


174 


CHEMISTRY. 


MARGARITIC  ACID. 

When  we  immerse  soap,  made  of  pork-grease  an  I 
potassa,  in  a  large  quantity  of  water,  one  part  is  dissolved, 
while  the  other  part  is  precipitated  in  the  form  of  seve¬ 
ral  brilliant  pellets.  These  are  separated,  dried,  washed 
in  a  large  quantity  of  water,  and  then  dried  on  a  filter : 
they  are  now  dissolved  in  boiling  alcohol,  specific  gra¬ 
vity  0.820 ;  from  which,  as  it  cools,  the  pearly  substance 
falls  down  pure.  On  acting  on  this  with  diluted  muriatic 
acid,  a  substance  of  a  peculiar  kind,  which  Chevreuil, 
the  discoverer,  calls  margarine,  or  margaritic  acid,  is 
separated.  It  must  be  well  washed  with  water,  dissolved 
in  boiling  alcohol ;  from  which  it  is  recovered,  in  the  same 
crystalline  form,  when  the  solution  cools. 

Margaric  acid  is  pearly  white,  and  tasteless.  Its 
smell  is  feeble,  and  a  little  similar  to  that  of  melted  wax. 
Its  specific  gravity  is  inferior  to  that  of  water.  It  melts 
at  134°  F.,  into  a  very  limpid,  colourless  liquid,  which 
crystallizes,  on  cooling,  into  brilliant  white  needles,  of 
the  finest  white.  It  is  insoluble  in  water,  but  very  solu¬ 
ble  in  alcohol,  specific  gravity  0.800.  Cold  margaric 
acid  has  no  action  on  the  colour  of  litmus;  but  when 
heated  so  as  to  soften  without  melting,  the  blue  was  red¬ 
dened.  It  combines  with  the  salifiable  bases,  and  forms 
neutral  compounds.  Two  orders  of  margarites  are 
formed,  the  margarites,  and  the  super-rnargcirites ;  the 
former  being  converted  into  the  latter  by  pouring  a  large 
quantity  of  water  on  them.  Other  fats,  besides  that  of 
the  hog,  yield  this  substance. 

That  of  man  is  obtained  under  three  different  forms. 
1.  In  very  fine  long  needles,  disposed  in  flat  stars.  2.  In 
very  fine  and  very  short  needles,  forming  waved  figures, 
like  those  of  the  margaric  acid  of  carcases.  3.  In  very 
large  brilliant  crystals,  disposed  in  stars,  similar  to  the 
margaric  acid  of  the  hog.  The  margaric  acids  of  man 
and  the  hog  resemble  each  other  ;  as  do  those  of  the  ox 
and  the  sheep ;  and  of  the  goose  and  the  jaguar.  The 
compounds  with  the  bases,  are  real  soaps.  The  solution 
in  alcohol  affords  the  transparent  soaps  of  this  country 


ME  CON  1C,  MELASSIC,  AND  MELLITIC  ACID.  175 

MECONIC  ACID. 

This  acid  is  a  constituent  of  opium.  It  was  discovered 
3y  Sertucrner,  who  procured  it  in  the  following  way : 
Alter  precipitating  the  morphia,  from  a  solution  oi 
opium,  by  ammonia  :  he  added  to  the  residual  fluid  a 
solution  of  muriate  of  barytes.  A  precipitate  is  in  this 
way  formed,  which  is  supposed  to'  be  a  quadruple  com¬ 
pound,  of  barytes,  morphia  extract,  and  the  meconic 
acid.  The  extract  is  removed  by  alcohol,  and  the 
barytes  by  sulphuric  acid;  when  the  meconic  acid  is 
left,  merely  in  combination  with  a  portion  of  the  morphia' 
from  this  it  is  purified  by  successive  solutions  and  evapO' 
rations.  The  acid,  when  sublimed,  forms  long  colourles? 
needles;  it  has  a  strong  affinity  for  the  oxide  of  iron,  sc 
as  to  take  it  from  the  muriatic  solutions,  and  form  with 
it  a  cherry-red  precipitate.  It  forms  a  crystallizable 
salt  with  lime,  which  is  not  decomposed  by  sulphuric 
acid,  and  what  is  curious,  it  seems  to  possess  no  particu¬ 
lar  power  over  the  human  body,  when  received  into  the 
stomach.  The  essential  salt  of  opium,  obtained  in 
Derosne's  original  experiments,  was  probably  the  meco* 
niate  of  morphia.  • 

Ilobiquet  has  made  a  useful  modification  of  the  pro¬ 
cess  for  extracting  meconic  acid,  tie  treats  the  opium 
with  magnesia,  to  separate  the  morphia,  while  meconiate 
of  magnesia  is  also  formed.  The  magnesia  is  removed 
by  adding  muriate  of  barytes,  and  the  barytes  is  after¬ 
wards  separated  by  dilute  sulphuric  acid.  A  larger  pro¬ 
portion  of  meconic  acid  is  thus  obtained. 

MELASSIC  ACID. 

The  acid  present  in  melassc-s,  which  has  been  thought 
a  peculiar  acid  by  some,  by  others  the  acetic. 

MELLITIC  ACID. 

Klaproth  discovered  in  the  mellilite,  or  honey  stone, 
what  he  conceives  to  be  a  peculiar  acid  of  the  vegetable 


CHEMISTRY. 


Ho 

kind,  eurfimned  with  alumina.  This  acid  is  easily  obtained 
by  reducing  the  stone  to  powder,  and  boiling  it  in  about 
seventy  times  its  weight  of  water;  when  the  acid  will 
dissolve,  and  may  be  separated  from  the  alumina  by 
Alteration.  By  evaporating  the  solution,  it  may  be  ob¬ 
tained  in  the  form  of  crystals.  The  following  are  its 
characters. 

It  crystallizes  in  fine  needles  or  globules  by  the  union 
of  these,  or  small  prisms.  Its  taste  is  at  first  a  sweetish- 
sour,  which  leaves  a  bitterness  behind.  On  a  plate  of 
hot  metal  it  is  easily  decomposed,  and  dissipated  in  copi¬ 
ous  grey  fumes,  which  affect  not  the  smell,  leaving 
behind  a  small  quantity  of  ashes,  that  do  not  change 
either  ied  or  blue  tincture  of  litmus.  Neutralized  by 
potassa,  it  crystallizes  in  groups  of  long  prisms:  by  soda, 
in  cubes,  or  triangular  laminae,  sometimes  in  groups,  some¬ 
times  single  ;  and  be  ammonia,  in  beautiful  prisms  with 
six  planes,  which  soon  lose  their  transparency,  and  ac¬ 
quire  a  silver-white  hue.  If  the  metallic  acid  be  dissolved 
in  lime  water,  and  a  solution  of  calcined  strontian  or 
barytes  be  dropped  into  it,  a  white  precipitate  is  thrown 
down,  which  is  re-dissolved  on  adding  muriatic  acid. 
With  a  solution  of  acetate  of  barytes,  it  produces  like¬ 
wise  a  white  precipitate,  which  nitric  acid  re-dissolvcs. 
With  a  solution  of  muriate  of  , barytes,  it  produces  no 
precipitate,  or  even  cloud  ;  but  after  standing  some  time, 
tine  transparent  ncedly  crystals  are  deposited.  The 
metallic  acid  produces  no  change  in  a  solution  of  nitrate 
of  silver.  From  a  solution  of  nitrate  of  mercury,  either 
hot  or  cold,  it  throws  down  a  copious  white  precipitate, 
which  an  addition  of  nitric  acid  immediately  re-dissolves. 
With  nitrate  of  iron  it  gives  an  abundant  precipitate  of 
a  dun  yellow  colour,  which  may  be  re-dissolved  by  muri¬ 
atic  acid.  With  a  solutibn  of  acetate  of  lead,  it  produces 
an  abundant  precipitate,  immediately  re-dissolved  on 
adding  nitric  acid.  With  acetate  of  copper,  it  gives  n 
greyish-green  precipitate;  but  it  does  not  effect  a  sol u 
tion  of  muriate  of  copper.  Lime-water  precipitated  by 
»t,  is  immediately  re-dissolved  on  adding  nitric  acid. 


MENISPERMIC  ACID,  MOLYBDIC  ACID.  I  77 

MENISPERMIC  ACID. 

The  seeds  of  menispcrmune  oculus,  being  macerated 
for  24  hours,  in  5  times  their  weight  of  water,  first  cold, 
and  then  boiling  hot,  yield  an  infusion,  from  which  solu¬ 
tion,  sub-acetate  of  lead  throws  down  a  menispermate 
of  lead.  This  is  to  be  washed  and  drained,  diffused 
through  .water,  and  decomposed  by  a  current  of  sulphu¬ 
retted  hydrogen  gas.  The  liquid  thus  freed  from  lead, 
is  to  be  deprived  of  sulphuretted  hydrogen  by  heat,  and 
then  forms  solution  of  menispermic  acid.  By  repeated 
evaporations  and  solutions  in  alcohol,  it  loses  its  bitter 
taste,  and  becomes  a  purer  acid.  It  occasions  no  precip¬ 
itate  with  lime-water;  with  nitrate  of  barytes  it  yields  a 
grey  precipitate ;  with  nitrate  of  silver,  a  deep  yellow ; 
and  with  sulphate  of  magnesia,  a  copious  precipitate. 

-  MOLYBDIC  ACID. 

Molybdic  acid  is  obtained  from  the  ore  or  sulphuret 
of  molybdenum,  by  distilling  nitric  ticid  off  it  repeatedly, 
till  the  sulphur  and  metal  are  both  acidified,  which  is 
known  by  the  conversion  of  the  whole  into  a  white  mass 
Hot  water  carries  off  the  sulphuric  acid,  and  leaves  the 
molybdic  acid  in  a  state  of  purity. 

Molybdic  acid  is  a  ydlowish-wdrite  powder ;  it  has  an 
acrid  but  metallic  taste.  It  is  not  altered  in  the  air,  and 
will  bear  a  strong  heat  if  the  crucible  be  covered;  but 
if  the  crucible  be  uncovered,  the  acid  rises  in  the  form 
of  a  white  smoke.  Its  specific  gravity  is  3.75.  It  re¬ 
quires  570  times  its  weight  ©f  water  to  dissolve  it.  The 
solution  has  a  sour  taste,  coagulates  solutions  of  soap,  and 
precipitates  alkaline  sulphurets.  Paper  dipped  in  this 
acid  becomes  of  a  beautiful  blue  colour  in  the  sun. 

The  molybdic  acid  has  not  been  applied  to  any  use  in 
the  arts,  though  experiments  have  been  made  which  indi¬ 
cate  that  it  may  become  useful  in  dyeing.  Its  combina¬ 
tions  with  different  bases  are  called  molybdates. 

M 


178 


CHEMISTRY. 


MOLYBDENOUS  ACID. 

Molybdena  is  susceptible  of  four  different  combinations 
with  oxygen  ;  at  the  lowest  it  is  in  a  state  of  black  oxides 
at  the  next  it  is  blue ;  at  the  third  it  begins  to  assume 
acid  properties,  and  is  green.  This  is  the  molybdenous 
acid.  The  next  dose  of  oxygen  forms  the  yellowish 
white  powder,  which  is  the  acid  treated  of  in  the  last 
section. 

MUCIC  ACID. 

This  acid  has  been  generally  known  by  the  name  of 
saccholactic,  because  it. was  first  obtained  from  sugar  of 
milk ;  but  as  all  the  gums  appear  to  afford  it,  and  the 
principal  acid  in  the  sugar  of  milk  is  the  oxalic,  chemists, 
in  general,  now  distinguish  it  by  the  name  of  mucic  acid. 

It  was  discovered  by  Scheele.  Having  poured  twelve 
ounces  of  diluted  nitric  acid  on  four  ounces  of  powdered 
sugar  of  milk,  in  a  glass  retort  on  a  sand  bath,  the  mix¬ 
ture  became  gradually  hot,  and  at  length  effervesced 
violently,  and  continued  to  do  so  for  a  considerable  time 
after  the  retort  was  taken  from  the  fire.  It  is  necessary 
therefore,  to  use  a  large  retort,  and  not  to  bite  the 
receiver  too  tight.  The  effervescence  having  nearly 
subsided,  the  retort  was  again  placed  on  the  sand  heat, 
and  the  nitric  acid  distilled  off,  till  the  mass  had  acquired 
a  yellowish  colour.  This  exhibiting  no  crystals,  eight 
ounces  more  of  the  same  acid  were  added,  and  the 
distillation  repeated,  till  the  y.ellow  colour  of  the  fluid 
disappeared.  As  the  fluid  was  inspissated  by  cooling,  it 
was  re-dissolved  in  eight  ounces  of  water,  and  filtered. 
The  filtered  liquor  held  oxalic  acid  in  solution,  and  seven 
drachms  and  a  half  of  white  powder  remained  on  the 
filter.  This  powder  was  the  acid  under  consideration. 

If  one  part  of  gum  be  heated  gently  with  two  of  nitric 
acid,  till  a  small  quantity  of  nitrous  gas  and  carbonic 
acid  is  disengaged,  the  dissolved  mass  will  deposit  on 
cooling  the  mucic  acid.  According  to  Fourcroy  and 
Vanquelinr  different  gums  yield  from  14  to  20  hundredths 
of  this  acid. 


MURIATIC  ACID.  179 

This  pulverulent  acid  is  soluble  in  about  sixty  parts  of 
hot  water,  and  by  cooling,  a  fourth  part  separates  in 
small  shining  scales,  that  grow  white  in  the  air.  It  de¬ 
composes  the  muriate  of  barytes,  and  both  the  nitrate 
and  muriate  of  lime.  It  acts  very  little  on  the  metals, 
but  forms  with  their  oxides  salts  scarcely  soluble.  It 
precipitates  the  nitrate  of  silver,  lead,  and  mercury. 
W  1th  potassa  it  forms  a  salt  soluble  in  eight  parts  of 
boding  water,  and  crystallizable  by  cooling.  That  of 
soda  requires  but  five  parts  of  water,  and  is  equally 
crystallizable.  .  Both  these  salts  are  still  more  soluble 
w  en  the  acid  is  in  excess.  That  of  ammonia  is  deprived 
of  its  base  by  heat.  The  salts  of  barytes,  lime,  and 
magnesia  are  nearly  insoluble. 

MURIATIC  ACID. 

Muriatic  acid,  so  generally  known  under  the  name  of 
spirit  of  salt,  or  marine  acid,  is  a  combination  of  oxy 

gen  with  an  unknown  base;  for  the  acid  has  never  been 
decomposed. 

In  its  combinations  it  is  very  abundant  in  the  mineral 
kingdom,  particularly  with  soda,  lime,  and  magnesia.  Its 
combination  with  soda  forms  common  salt,  and  the  affinity 
of  the  two  substances  is  such,  that  they  are  not  separated 
oy  a  heat  which  volatilizes  salt.  In  obtaining  this  acid 
from  muriate  of  soda,  therefore,  some  substances  must 
be  used  which  will  combine  with  the  alkali.  Sulphuric 
acid,  or  substances  which  contain  it,  such  as  clay  are 
generally  used.  Mix  one  part  of  sulphuric  acid  with 
two  parts  of  dry  muriate  of  soda,  in  a  glass  rotort,  apply 
<i  gentle  heat,  and  use  the  mercurial  pneumatic  trough 
to  collect  the  product  which  comes  over.  The  product 
is  muriatic  acid  in  a  state  of  gas.  This  gaseous  acid  is 
invisible,  and  elastic,  like  common  air,  but  has  about 
twice  its  specific  gravity.  It  has  a  pungent,  suffocating 
smell,  and  it  is  extremely  caustic. 

Muriatic  acid  gas  absolves  water  with  avidity.  Water 
vvdl  combine  with  its  weight  of  the  gas,  and  the  specific 


CHEMISTRY. 


ISO 

gravity  of  the  liquid  muriatic  acid  thus  obtained  is  1.5 
it  is,  however,  not  easily  procured  and  preserved  of  a 
greater  specitic  gravity  than  1.190. 

Liquid  muriatic  acid  is  generally  of  a  pale  yellow 
colour,  hut  this  colour  is  attributed  to  the  presence  of 
some  impurity;  it  preserves  the  smell  of  the  gas,  is  very 
volatile,  and  gives  out  white  fumes  by  exposure  to  the 

atmosphere.  . 

♦  .  It  is  capable,  by  the  assistance  of  heat,  of  oxidizing 
iron,  tin,  lead,  zinc,  bismuth,  cobalt,  nickel,  manganese, 
antimony,  and  arsenic.  At  a  boiling  heat,  it  oxidizes 
silver  and  copper.  On  gold,  platina,  mercury,  tungsten, 
molybdenum,  tellurium,  and  titanium,  it  has  no  action. 

The  proper  solvent  for  gold  and  platina,  is  the  nilro- 
muriatic  acid,  composed  of  one  part  of  muriatic,  and 
two  of  nitric  acid. 

Muriatic  acid  is  the  best  test  for  silver.  A  single  drop 
of  it  poured  into  a  solution  containing  this  metal  will 
cause  a  copious  precipitate. 

Muriatic  acid,  combined  with  different  bases,  forms  the 
salts  called  muriates. 

This  acid,  in  thq  state  of  gas,  has  a  powerful  effect  in 
neutralizing  putrid  effluvia.  Morveau,  by  pouring  two 
pounds  of  sulphuric  acid  upon  six  pounds  of  common 
salt,  and  having  the  mixture  on  a  common  house  furnace 
'  of  live  coal,  completely  destroyed  the  putrid  exhalations 
which  had  caused  the  cathedral  of  Dijon  to  be  deserted. 


NITRIC  ACID. 

Nitric  acid  is  formed  by  the  chemical  union  of  about 
25  parts  by  weight  of  nitrogen,  with  75  parts  of  oxygen. 
Ry  mixing  nitrogen  and  oxygen  in  these  proportions, 
and  passing  a  number  of  electrical  shocks  through  the 
mixture,  nitric  acid  is  produced.  In  other  words,  the 
combustion  of  nitrogen  produces  nitric  acid. 

Nitric  acid,  combined  with  potass,  form  the  salt  called 
nitrate  of  -potass ,  or  saltpetre,  and  it  is  by  the  decom¬ 
position  of  this  salt,  that  it  may  be  procured.  If  threo 


NITRIC  ACID. 


181 


parts  of  nitrate  of  potass,  with  one  of  sulphuric  acid,  be 
distilled,  the  nitric  acid,  mixed  with  a  small  proportion 
of  nitrous,  comes  over.  The  nitrous  acid  may  be  expel¬ 
led  by  a  gentle  heat.  Nitric  acid  is  clear  and  colourless, 
like  water;  it  corrodes  animal  substances,  and  stains  the 
human  skin  a  permanent  yellow.  Its  smell  is  remark¬ 
ably  pungent,  and  its  taste  strongly  acid;  in  short,  it 
eminently  possesses  all  the  properties  enumerated  as 
peculiar  to  acids.  The  action  of  light  alone  will,  how¬ 
ever,  separate  a  part  of  its  oxygen,  and  cause  it  to 
assume  a  yellow  colour. 

Nitric  acid  has  a  strong  affinity  for  water,  and  has 
never  been  obtained  except  in  combination  with  it. 
When  concentrated,  it  attracts  moisture  irom  the  atmo¬ 
sphere,  but  not  so  powerfully  as  the  sulphuric  acid. 
When  mixed  with  water,  it  produces  heat,  but  not  in 
equal  degree  with  the  sulphuric  acid.  It  boils  at  248°. 
When  concentrated  to  the  utmost,  its  specific  gravity  is 
about  1.5.  When  diluted  with  water,  it  is  sold  under 
i  the  name  of  aquafortis  :  even  the  double  aquafortis  of 
the  stores  sold  is  only  about  halt  the  strength  of  nitric 
acid. 

Nitric  acid  is  easily  decomposed,  and  it  therefore  con¬ 
stitutes  a  valuable  agent  to  the  chemist.  It  is  capable 
of  oxidizing  all  the  metals,  except  gold  and  titanium ; 
and  even  gold  it  appears  to  attack  in  a  slight  degree. 
If  brought  into  contact  with  hydrogen  at  a  slight  tem¬ 
perature,  a  violent  detonation  is  produced.  It  mixed 
with  oils,  it  sets  them  on  fife,  and  both  the  acid  and  the 
oil  is  decomposed.  The  oils  should  be  free  from  water, 
but  as  this  is  rarely  the  case,  the  experiment  is  most  cer¬ 
tain  of  success  if  a  little  sulphuric  acid  be  mixed  with 
the  nitric  acid,  as  that  acid  will  combine  with  the  water. 
Oils  deprived  of  water  by  boiling,  inflame  with  nitric 
acid  alone.  In  making  these  mixtures,  the  operator 
should  keep  himself  at  a  distance  from  them,  by  using 
vessels  with  long  handles. 

Perfectly  dry  charcoal  is  also  inflamed  by  nitric  acid  , 
with  dry  filings  of  iron  the  same  effect  takes  place ;  and 
16 


182 


CHEMISTRY. 


also  with  zinc,  and  tin,  if  the  acid  be  poured  upon  them 
in  fusion. 

The  nitric  acid,  with  the  alkalies,  alkaline  earths,  alu 
mine,  zircon,  and  the  oxides  of  metals,  form  the  salt* 
called  nitrates. 

NITROUS  ACID. 

According  to  the  principles  of  the  new  nomenclature, 
there  is  no  acid  strictly  entitled  to  the  appellation  of  ni¬ 
trous  acid :  the  acid  which  obtains  this  name  is  not  the 
acid  of  nitre  with  a  minimum  of  oxygen,  but  nitric  acid, 
combined  with  different  proportions  of  nitric  oxide ;  of 
which  an  account  will  be  found  under  the  head  of 
oxides. 

Nitrous  acid  is  more  or  less  coloured,  according  to  the 
quantity  of  nitric  oxide  with  which  it  is  impregnated.  It 
parts  with  the  gas  very  readily;  which,  when  in  quan¬ 
tity*  passes  of!  in  vapours  that  assume  a  red  colour  on 
mixing  with  the  atmosphere.  On  account  of  the  extri¬ 
cation  of  these  vapours,  the  acid  is  sometimes  called 
fuming  aquafortis.  1  he  addition  of  different  portions  of 
water  causes  nitrous  acid  to  appear  blue,  e;reen,  yellow, 
&c. ;  but  the  vapours  are  always  of  the  same  red  hue. 

The  general  properties  of  nitrous  acid  are  similar  to 
those  of  the  nitric ;  with  different  bases,  it  forms  the 
salts  called  nitrates.  These  are  not  formed  by  the  di¬ 
rect  union  of  their  component  parts ;  but  bv  exposing 
nitrates  to  a  high  temperature,  which,  separating  a  part 
of  their  oxygen,  leaves  them  in  the  state  of  nitrates. 

NITROLEUCIC  ACID. 

This  acid  is  so  named  from  its  being  obtained  by  the 
action  o(  nitric  acid  on  leucine.  Leucine  is  capable  of 
uniting  to  nitric  acid,  and  forming  a  compound,  which 
Braconnct  has  called  the  nitroleucic  acid.  When  we 
dissolve  leucine  in  nitric  acid,  and  evaporate  the  solution 
to  a  certain  point,  it  passes  into  a  crystalline  mass,  with¬ 
out  any  disengagement  of  nitrous  vapour,  or  of  anv 


NITRO-MURIATIC,  NITRO-SULPHURIC,  OLEIC.  183 

gaseous  matter.  If  we  press  this  mass  between  blotting- 
paper,  and  dissolve  it  in  water,  we  shall  obtain  from 
this,  by  concentration,  fine  divergent,  and  nearly  colour¬ 
less  needles.  These  constitute  the  new  acid.  It  unites 
to  the  bases,  forming  salts  which  fuse  on  red-hot  coals. 
The  nitro-leucates  of  lime  and  magnesia  are  unalterable 
in  the  air. 

NITRO-MURIATIC  ACID. 

Jlqua  regia.  When  nitric  and  murialic  acids  are 
mixed,  they  become  yellow,  and  acquire  the  power  of 
readily  dissolving  gold,  which  neither  of  the  acids  pos¬ 
sessed  separately.  This  mixture  evolves  chlorine,  a  par¬ 
tial  decomposition  of  both  acids  having  taken  place ;  and 
water,  chlorine,  and  nitrous  acid  gas  are  thus  produced : 
that  is,  the  hydrogen  of  the  muriatic  acid  abstracts  oxy¬ 
gen  from  the  nitric,  to  form  water.  The  result  must  be 
chlorine  and  nitrous  acid. 

NITRO-SULPIIURIC  ACID. 

A  compound  consisting  of  one  part  of  nitre  dissolved 
in  about  ten  of  sulphuric  acid. 

OLEIC  ACIlX 

When  potassa  and  hogs’  lard  are  saponified,  the  mar- 
garate  of  the  alkali  separates  in  the  form  of  a  pearly- 
looking  solid,  while  the  fluid  fat  remains  in  solution, 
combined  with  the  potassa.  When  the  alkali  is  sepa¬ 
rated  by  tartaric  acid,  the  oily  principle  of  fat  is  ob¬ 
tained,  which  Chevreuil  purifies  by  saponifying  it  again, 
and  again  recovering  it  two  or  three  times;  by  which 
means  the  whole  of  the  margarine  is  separated.  As  this 
oil  has  the  property  of  saturating  bases,  and  forming 
neutral  compounds,  he  has  called  it  oleic  acid. 


184 


CHEMISTRY. 


OXALIC  ACID. 

The  oxalic  acid  exists  in  the  juice  of  the  wood-sorrel, 
combined  with  potass.  When  prepared  from  this  plant, 
it  is  sold  under  the  name  of  salt  of  lemons;  and  is  used 
as  a  substitute  for  the  real  juice  of  lemons.  Sugar,  and 
all  other  saccharine  substances,  contain  the  radical  of 
the  very  same  acid  which  wood-sorrel  affords.  It  may 
be  extracted  from  sugar  in  the  following  manner : 

To  six  ounces  of  nitric  acid,  in  a  tubulated  retort,  t 
which  a  large  receiver  is  luted,  add,  by  degrees,  one 
ounce  of  lump  sugar,  coarsely  powdered.  A  gentle  heat 
may  be  applied  during  the  solution,  and  nitric  oxide  will 
be  evolved  in  abundance.  When  the  whole  of  the 
sugar  is  dissolved,  distil  oil’  a  part  of  the  acid,  till  what 
remains  in  the  retort  has  the  consistence  of  a  syrup, 
and  this  will  form  regular  crystals,  amounting  to  58 
parts  from  100  of  sugar.  These  crystals  may  be  dis¬ 
solved  in  water,  re-crystallized,  and  dried  on  blotting- 
paper. 

Honey,  gum  arabic,  alcohol,  the  calculous  concre¬ 
tions  in  the  kidneys  and  bladders  of  animals,  silk,  wool, 
hair,  and  various  other  bodies,  afford  oxalic  acid,  by 
distillation  with  nitric  acid.  Berthollet  observes,  that 
the  quantity  of  the  acid  afforded  by  vegetable  matters 
is  in  proportion  to  their  nutritive  qualities. 

The  crystals  of  oxalic  acid  effloresce  in  dry  air,  but 
attract  a  little  humidity  if  it  be  damp.  They  are  solu¬ 
ble  in  one  part  of  hot,  and  two  parts  of  cold  water;  and 
are  decomposed  by  a  red  heat.  When  dissolved  in 
3G00  times  their  weight  of  water,  the  solution  still  red¬ 
dens  litmus-paper,  and  is  perfectly  acid  to  the  taste. 

The  oxalic  acid  is  a  good  test  for  lime,  for  which  it 
has  a  greater  atlinity  than  any  other  acid.  It  forms  with 
lime,  an  insoluble  salt,  not  decomposable  except  by  fire, 
and  turning  syrup  of  violets  green. 

Oxalic  acid  is  .capable  of  oxalizing  lead,  copper,  iron, 
tin,  bismuth,  nickel,  cobalt,  zinc,  and  manganese. 

The  combination  of  oxalic  acid  with  the  alkalies  and 
other  bases,,  form  the  salts  called  oxalates. 


OXYMURIATIC  ACID. 


i  sr» 

Oxalic  acid  dissolved  in  water  is  employed  by  calico 
printers  to  destroy  or  lighten  colours  which  are  produced 
by  iron.  It  is  also  used  to  remove  iron  moulds,  and  to 
take  out  spots  of  ink  from  furniture,  and  various  other 
articles,  which  it  does  with  the  greatest  facility.  The 
crystals  of  oxalic  acid  much  resemble  those  of  Epsom 
salt  which  are  much  used  as  a  purgative :  several  unfor¬ 
tunate  accidents  have  happened  through  its  having  been 
taken  by  mistake,  as  the  corrosive  power  of  this  acid  is 
very  great,  when  taken  in  so  large  a  dose  as  Epsom  salt. 

OXYMURIATIC  ACID. 

If  84  parts  of  muriatic  acid  be  combined  with  1G  of 
oxygen,  they  form  oxymuriatic  acid.  This  combination 
is  usually  formed  by  adding  to  one  part  of  the  black  ox¬ 
ide  of  manganese,  two  parts  of  strong  muriatic  acid,  and 
distilling  the  mixture  with  a  gentle  heat.  The  gas  ob¬ 
tained  is  received  over  water,  by  means  of.  pneumatic 
apparatus. 

Oxymuriatic  acid  gas  is  tinged  of  a  yellow  colour  by 
contact*  with  atmospheric  air;  it  supports  flame,  but 
cannot  be  breathed  without  the  most  injurious  effects. 
Pelletier  having  attempted  to  respire  it,  the  consequence 
was  a  consumption,  which  in  a  short  time  put  a  period 
to  his  life.  If  it  happen  to  be  accidentally  inhaled,  the 
vapour  of  volatile  alkali,  for  which  it  has  a  strong  affinity, 
is  the  best  remedy.  It  does  not  readily  unite  with  water; 
and  at  the  temperature  of  freezing  water  it  crystallizes. 

Other  acids  become  more  intensely  sour  by  an  ad¬ 
ditional  dose  of  oxygen,  but  the  muriatic  has  this  pro¬ 
perty  diminished  by  the  same  addition.  The  taste  of 
oxymuriatic  acid  is  harsh  and  styptic,  and  instead  of 
reddening  vegetable  colours,  it  changes  them  all  to  white, 
and  their  colours  cannot  be  restored  either  by  acids  or 
alkalies.  On  this  account,  it  has  been  extensively  used 
in  the  process  of  bleaching.  After  having  thus  been 
employed  upon  a  sufficient  quantity  of  materials,  it  is 
16  * 


186 


CHEMISTRY. 


converted  into  common  muriatic  acid.  It  has,  therefore, 
produced  its  effect  by  imparting  oxygen. 

As  the  oxymuriatic  acid  eradicates  writing-ink,  but 
nas  no  effect  upon  printing-ink,  it  may  be  conveniently 
used  for  whitening  soiled  books  and  prints;  it  removes 
all  stains  but  those  of  an  oily  nature.  An  easy  mode  of 
preparing  a  cjuantity  of  it,  consists  in  adding  one  ounce 
of  the  red  oxide  of  lead  to  three  ounces  of  muriatic. 
The  red  lead  supplies  the  oxygen  which  oxygenizes  the 
acid.  This  preparation  should  not  be  made  till  near  th 
time  against  which  it  is  wanted,  and  when  made  it 
should  be  kept  in  the  dark,  as  it  is  deoxygenized  by  the 
light. 

The  nitromuriatic  and  oxymuriatic  acids  have  the 
same  appearance  and  odour,  as  well  as  the  same  effects, 
as  solvents.  It  appears,  therefore,  that  the  nitric  acid, 
when  added  to  the  muriatic,  has  only  the  effect  of  sup¬ 
plying  it  with  oxygen.  . 

Oxymuriatic  acid  oxidizes  nearly  all  the  metals  with 
out  the  assistance  of  heat.  It  decomposes  the  red  sul- 
phuret  of  mercury,  which  neither  the  sulphuric  nor  the 
nitric  acid  will  accomplish.  It  may  be  combined  with  a 
great  number  of  bases;  the  salts  which  it  forms  detonate 
with  carbon  and  several  metallic  substances.' 

Hyper-oxymuriate  of  j)otass  is  made  by  introducing 
the  oxymuriatic  acid  gas  into  a  solution  of  potass;  its  crys¬ 
tals,  as  well  as  those  of  common  muriate,  being  formed 
by  evaporation  in  the  dark.  It  gives  a  faint  taste,  with 
a  sensation  of  coldness  in  the  mouth;  the  crystals  have 
somewhat  of  a  silvery  appearance,  and  emit  light  By 
attrition.  It  is  decomposed  by  the  action  of  light,  part¬ 
ing  with  oxygen,  and  becoming  simple  muriate  of  potass. 
Heat  also  separates  its  oxygen  in  the  form  of  gas;  100 
grains  of  it  will  yield  75  cubic  inches  of  oxygen  gas. 

When  three  parts  of  hyper-oxymuriate  of  potass,  and 
one  of  sulphur,  are  triturated  in  a  mortar,  the  mixture 
detonates  violently.  The  same  effect  is  produced  when 
the  mixture  is  struck  with  a  hammer  upon  an  anvil. 

Phosphorus  and  hyper-oxymuriate  of  potass  detonato 
with  prodigious  force. 


PHOSPHORIC  ACID. 


18? 


Exotic  seeds  which  could  not  be  caused  to  germinate 
Dy  ordinary  means,  have  germinated  after  being  steeped 
or  a  few  days  in  weak  oxymuriatic  acid. 

PHOSPHORIC  ACID. 

The  purest  phosphoric  acid  is  obtained  by  the  com 
bustion  of  phosphorus  in  oxygen  gas.  If  no  moisture  be 
present,  it  is  obtained  in  the  form  of  white  flocks,  which 
are  very  light,  and  have  a  strongly  acid  taste.  These 
flocks  will  attract  moisture  from  the  atmosphere,  and 
become  a  fluid  acid.  This  acid  may  be  concentrated 
till  its  specific  gravity  exceeds  that  of  the  sulphuric 
acid ;  though  strongly  acrid,  it  is  not  corrosive,  and  has 
no  smell. 

Phosphoric  acid  may  likewise  be  obtained  by  heating 
phosphorus  with  nitric  or  sulphuric  acid  ;  it  remains  in 
the  retort,  after  these  acids  are  driven  over.  Another 
mode  of  forming  it,  consists  in  exposing  phosphorus  for 
some  weeks  to  the  common  temperature  of  the  atmo¬ 
sphere,  by  which  means  it  is  gradually  converted  into  a 
liquid  acid.  It  is  usually  placed  on  the  inclined  side  of  a 
funnel,  through  which  the  liquid  which  is  formed  drops 
into  a  bottle  placed  beneath  to  receive  it,  and  contain¬ 
ing  a  little  distilled  water.  The  acid  thus  prepared,  is 
ca lied  phosphoric  acid  by  deliquescence. 

The  quantity  of  acid  obtained  from  phosphorus,  is 
generally  about  three  times  the  weight  of  the  phos¬ 
phorus  used. 

K  phosphoric  acid  be  exposed  to  heat,  it  gradually 
becomes  thick  and  -glutinous ;  and  if  the  heat  be  con¬ 
tinued,  it  melts  into  a  kind  of  glass,  which  is  called  the 
glacial  acid  of  phosphorus,  or  glacial  phosphoric  acid. 
This  glacial  acid  becomes  liquid  by  exposure  to  the 
atmosphere. 

Phosphoric  acid,  when  perfectly  dry,  sublimes  in  close 
vessels,  but  the  addition  of  water  deprives  it  of  this  pro¬ 
perty.  If  mixed  with  charcoal,  or  other  inflammable 
matter,  and  exposed  to  a  strong  heat,  it  parts  with  its 
oxygen,  and  is  converted  into  phosphorus. 


CHEMISTRY. 


1 88 

Phosphoric  acid,  assisted  by  heat,  has  some  action 
upon  silex,  and  will,  therefore,  decompose  glass. 

The  salts  of  phosphorus  are  called  phosphates.  The 
phosphate  of  lime  exists  in  bones,  from  which  phospho¬ 
rus  is  generally  prepared.  Whole  mountains  of  phos¬ 
phate  of  lime  are  said  to  exist  in  the  province  of  Estre- 
madura,  in  Spain. 

PHOSPHOROUS  ACIU. 

The  spontaneous  combustion  of  phosphorus  at  the 
temperature  of  the  atmosphere,  forms,  in  the  first  in¬ 
stance,  phosphorous  acid,  which  contains  less  oxygen 
than  the  phosphoric ;  but,  as  phosphorous  acid  acquires 
an  additional  quantity  of  oxygen  from  the  atnrtosphere, 
it  is  speedily  convertedinto  the  phosphoric. 

Phosphorous  acid  is,  therefore,  very  little  known.  It 
may,  therefore,  be  decomposed  by  charcoal ;  but  cannot 
be  reduced  to  the  glacial  state.  Its  salts  are  called 
phosphates. 

PRUSSIC  ACID. 

This  acid  exists,  combined  with  iron,  in  the  fine  blue 
pigment,  well  known  by  the  name  of  Prussian  blue.  It 
may  be  obtained  as  follows:  mix  four  ounces  of  Prussian 
blue  with  two  of  red  oxide  of  mercury,  prepared  by  ni¬ 
tric  acid,  and  boil  them  in  twelve  ounces,  by  weight,  of 
water,  till  the  whole  becomes  colourless;  filter  the  liquor, 
and  add  to  it  one  ounce  of  clean  iron  filings,  and  six  or 
seven  drachms  of  sulphuric  acid  :  drain  olF,  by  distillation, 
about  a  fourth  of  the  liquor,  which  will  be  prussic  acid ; 
though,  as  it  is  liable  to  be  contaminated  with  a  portion 
of  sulphuric  acid,  to  render  it  pure,  it  may  be  rectified 
by  re-distilling  it  olF  carbonate  of  lime. 

The  prussic  acid  has  a  smell  like  that  of  peach  blos- 
>oms.  Its  taste  is  at  first  sweetish,  then  acid  and  hot, 
and  it  excites  coughing.  It  is  very  volatile,  and  capable 
>f  existing  in  an  acid  in  the  gaseous  form. 

The  prussic  acid  combines  with  earths,  alkalies,  and 


PltUSSIC  ACID. 


189 


metallic  oxides,  forming  the  salts  called  prussicitcs.  The 
prussiale  of  potash  and  iron,  often  called  the  prussian 
alka'ii,  is  one  of  the  most  important  of  these  compounds, 
both  for  its  utility  as  a  test,  and  for  making  prussian  blue. 
To  form  it,  two  parts  of  bullock’s  blood,  and  one  of 
potash,  are  calcined  by  a  moderate  heat  in  a  covered 
crucible,  containing  a  hole  in  the  lid.  The  calcination 
is  to  be  discontinued  when  the  matter  ceases  to  afford  a 
small  blue  flame.  The  residuum  must  be  lixiviated  with 
a  small  quantity  of  cold  water.  In  this  state,  the  prus- 
siate  of  potass  may  be  employed  for  making  prussian 
blue,  though  not  pure  enough  for  the  use  of  the  chemist. 
Henry  recommends  it  to  be  obtained  by  the  following 
process  from  prussian  blue,  when  required  quite  pure  : 
To  a  solution  of  potass,  deprived  of  its  carbonic  acid  by 
quick-lime,  and  heated  nearly  to  the  boiling  point,  add 
by  degrees  powdered  prussian  blue,  till  its  colour  ceases 
to  be  discharged.  Filter  the  liquor,  wash  the  sediment 
with  water,  till  it  ceases  to  extract  any  thing,  mix  the 
washings  together,  and  pour  the  mixture  into  an  earthen 
dish  in  a  sand-heat.  When  the  solution  has  become  hot, 
add  a  little  diluted  sulphuric  acid,  and  continue  the  heat 
about  an  hour.  A  copious  precipitate  of  prussian  blue 
will  be  formed,  which  must  be  separated  by  Alteration. 
Assay  a  small  quantity  of  the  filtered  liquor  in  a  wine¬ 
glass,  with  a  little  diluted  sulphuric  acid.  If  an  abundant 
production  of  prussian  blue  still  take  place,  the  whole 
liquor  must  be  exposed  again  to  heat  with  a  little  diluted 
sulphuric  acid,  and  this  must  be  repeated  as  often  as  is 
necessary.  Into  the  liquor  thus  far  purified,  pour  a  solu¬ 
tion  of  sulphate  of  copper  in  four  or  six  times  its  weight 
of  warm  water,  as  long  as  a  reddish  brown  precipitate 
continues  to  appear.  Wash  the  precipitate,  which  is  a 
prussiate  of  copper,  with  repeated  effusions  of  warm 
water  ;  and  when  the  water  comes  off  colourless,  lay  the 
precipitate  on  a  linen  filter  to  drain,  after  which  it  maj 
be  dried  on  a  chalk-stone.  When  the  precipitate  is  dry, 
powder  it,  and  add  it  by  degrees  to  a  solution  of  potass, 
which  will  take  the  prussic  acid  from  the  oxide  of  copper. 


CHEMISTRY. 


190 

This  prussiatc  of  potass,  however,  will  be  contaminated 
by  some  portion  of  sulphate  of  potass,  from  part  of 
which  it  may  be  freed  by  gentle  evaporation,  as  the  sul¬ 
phate  crystallizes  first.  To  the  remaining  liquor,  add  a 
solution  of  barytes  in  warm  water,  as  long  as  a  white 
precipitate  ensues,  observing  not  to  add  more  after  its 
cessation.  The  solution  of  prussiate  of  potass  will  now 
be  freed  in  a  great  measure  from  iron,  and  entirely  from 
sulphate,  and  hy  gentle  evaporation,  will  form,  on  cooling, 
beautiful  crystals.  These,  dissolved  in  cold  water,  afl'ord 
the  purest  prussian  alkali  that  can  be  prepared.  If 
pure  barytes  be  not  at  hand,  acetate  of  barytes  may  be 
used  instead ;  as  the  acetate  of  potass  formed,  not  being 
crystallizable,  will  remain  in  the  mother-water. 

Prussiates  of  soda  and  of  ammonia  may  be  prepared 
in  a  similar  way  to  the  prussiate  of  potass,  above  de¬ 
scribed. 

PYROLIGNEOUS  ACID. 

In  the  destructive  distillation  of  wood,  an  acid  is 
obtained,  which  was  formerly  called  acid  spirit  of  icood, 
and  since  pyroligneous  acid.  Fourcroy  and  Yanquelin 
showed  that  this  acid  was  merely  the  acetic  contamina¬ 
ted  with  empyreumatic  oil  and  bitumen. 

Monge  discovered,  that  this  acid  has  the  properly  of 
preventing  the  decomposition  of  animal  substances.  Mr. 
Win.  Dinsdale,  of  Field  Cottage,  Colchester,  three  years 
prior  to  the  date  of  Monge’s  discovery,  did  propose  to 
the  Lord  Commissioners  of  the  Admiralty,  to  apply  a 
pyroligneous  acid,  prepared  out  of  the  contact  of  iron 
vessels,  which  blacken  it,  to  the  purpose  of  preserving 
animal  food,  wherever  their  ships  might  go.  As  this 
application  may  in  many  places  afford  valuable  anti¬ 
scorbutic  articles  of  food,  and  thence  might  be  eminently 
conducive  to  the  health  of  seamen;  it  is  to  be  hoped 
that  Mr.  Dinsdale’s  ingenious  plan  might  be  carried  into 
effect,  as  far  as  is  deemed  necessary.  It  is  sufficient  to 
plunge  meat  for  a  few  moments  into  this  acid,  even 
slightly  empyreumatic,  to  preserve  it  as  long  as  you 


PYROLIGNEOUS  ACID. 


191 


please.  Putrefaction,  it  is  said,  not  only  stops  hut  retro¬ 
grades.  To  the  empyreumatic  oil  a  part  of  this  effect 
has  been  ascribed  ;  and  hence  has  been  accounted  for, 
the  agency  of  smoke  in  the  preservation  of  tongues, 
hams,  herrings,  &e.  Dr.  Jorg,  of  Leipsic,  has  entirely 
recovered  several  anatomical  preparations  from  incipient 
corruption  by  pouring  this  acid  over  them.  With  the 
empyreumatic  oil  or  tar  lie  has  smeared  pieces  of  flesh 
already  advanced  in  decay,  and  notwithstanding  that  the 
weather  was  hot,  they  soon  became  dry  and  sound.  Mr. 
Ramsey  has  added  the  following  facts  in  the  5th  number 
of  the  Edinburgh  Philosophical  Journal.  If  fish  be  sim¬ 
ply  dipped  in  redistilled  pyroligneous  acid,  of  the  specific 
gravity  1.012,  and  afterwards  dried  in  the  shade,  they 
preserve  perfectly  well.  On  boiling  herrings  treated  in 
this  manner,  they  were  very  agreeable  to  the  taste,  and 
had  nothing  of  the  disagreeable  empyreuma  which  those 
of  his  earlier  experiments  had,  which  were  steeped  for 
three  hours  in  the  acid.  A  number  of  very  fine  had¬ 
docks  were  cleaned,  split,  and  slightly  sprinkled  with  salt 
for  six  hours.  After  being  drained,  they  were  dipped  for 
about  three  seconds  in  pyroligneous  acid,  then  hung  up 
in  the  shade  for  about  six  days.  On  being  broiled,  the 
fish  were  of  an  uncommon  fine  flavour,  and  delicately 
white.  Reef  treated  in  the  same  way,  had  the  same 
flavour  as  the  Hamburgh  beef,  and  kept  as  well.  Mr. 
Ramsey  has  since  found,  that  his  perfectly  purified  vine¬ 
gar,  specific  gravity  1.034,  being  applied  by  a  cloth  or 
spunge  to  the  surface  of  fresh  meat,  makes  it  keep  sweet 
and  sound  for  many  days  longer  in  summer,  than  it  other¬ 
wise  would.  Immersion  for  a  minute  in  his  purified 
common  vinegar,  specific  gravity  1.009,  protects  beef  and 
fish  from  all  taints  in  summer,  provided  they  be  hung  up 
and  dried  in  the  shade.  When  by  frequent  use  the 
pyroligneous  acid  has  become  impure,  it  may  be  clarified 
by  beating  up  20  gallons  of  it  with  a  dozen  of  eggs  in 
the  usual  manner,  and  heating  the  mixture  in  an  iron 
boiler.  Before  boiling,  the  eggs  coagulate,  and  bring  the 
impurities  to  the  surface  of  the  boiler,  and  are  of 


192 


CHEMISTRY. 


course  to  be  carefully  skimmed  off!  The  acid  must  be 
immediately  withdrawn  from  the  boiler,  as  it  acts*  on 
iron. 

This  acid  has  long  been  prepared  for  the  calico-print¬ 
ers.  The  following  arrangement  of  apparatus  has  been 
found  to  answer  very  well.  A  series  of  cast-iron  cylin¬ 
ders,  about  four  feet  diameter,  and  six  feet  long,  are  set 
in  pairs,  horizontally,  in  brick-work,  so  that  the  flame 
of  one  fire  may  play  round  both.  Both  ends  project  a 
little  from  the  brick-work  :•  one  of  them  has  a  cast-iron 
plate  well  fitted,  and  firmly  bolted  to  it,  from  the  centre 
of  which,  an  iron  pipe,  about  six  inches  in  diameter, 
proceeds,  and  enters,  at  a  right  angle,  the  main  cool¬ 
ing-pipe.  The  diameter  of  this  main  pipe  may  be  from 
9  to  14  inches,  .according  to  the  number  of  cylinders. 
The  other  end  of  the  cylinder  is  called  the  mouth  of  the 
retort.  This  is  closed  by  an  iron  plate,  smeared  round 
its  edge  with  clay,  and  secured  in  its  place  by  wedges. 
The  charge  of  wood  for  such  cylinders  is  about  8  cwt. 

The  hard  woods,  oak,  ash,  birch,  and  beech,  are  alone 
used;  but  fir  does  not  answer.  The  heat  is  kept  up 
during  the  day-time,  and  the  furnace  is  allowed  to  cool 
during  the  night.  Next  morning,  the  door  is  opened,  the 
charcoal  is  removed,  and  a  new  charge  of  wood  is  intro¬ 
duced.  The  average  product  of  wood  vinegar,  or  raw 
pyroligneous  acid,  is  thirty-five  gallons.  It  is  much  con¬ 
taminated  with  tar,  is  of  a  deep  brown  colour,  and  has  a 
specific  gravity  of  1.025 ;  so  that  its  weight  is  about  3 
cwt. ;  but  the'  residuary  charcoal  is  found  to  weigh  no 
more  than  one-fifth  of  the  wood  employed. 

The  raw  pyroligneous  is  rectified  by  a  second  distilla¬ 
tion  in  a  copper-still,  in  the  body  of  which,  about  20  gal¬ 
lons  of  viscid  tarry  matter  is  lelt  from  every  100  of 
vinegar,  and  then  passes  over  a  transparent,  but  brown 
vinegar,  having  a  considerable  smell,  and  its  specific 
gravity  is  1.013.  Its  acid  powers  are  superior  to  those 
of  the  best  wine  or  malt  vinegar,  in  the  proportion  of 
three  to  two. 


RUCUMIC,  IIOSACJC,  AND  SEBACIC  ACID.  193 

RUCUMIC  ACID. 

4 

Ax  acid  said  to  be  peculiar  to  rhubarb,  but  not  yet 
sufficiently  examined. 

ROSACIC  ACID. 

There  is  deposited  from  the  urine  of  persons  labour¬ 
ing  under  gout  and  inflammatory  fevers,  a  sediment  of  a 
rose  colour,  occasionally  in  reddish  crystals.  It  was  at 
first  discovered  to  be  a  peculiar  acid  by  M.  Proust,  and 
afterwards  examined  by  M.  Vanquelin.  This  acid  is 
solid,  of  a  lively  cinnabar  hue,  without  smell,  with  a 
faint  taste,  but  reddening  litmus  very  sensibly.  On 
burning  coal  it  is  decomposed  into  a  pungent  vapour, 
which  has  not  the  odour  of  burning  animal  matter.  It  is 
very  soluble  in  water,  and  even  softens  in  the  air.  It  is 
soluble  in  alcohol.  It  forms  soluble  salts  with  potassa, 
soda,  ammonia,  barytes,  strontites,  and  lime.  It  gives  a 
slight  rose-coloured  precipitate,  with  acetate  of  lead.  It 
also  combines  with  lithic  acid,  forming  so  intimate  a 
union,  that  the  lithic  acid  in  precipitating  from  urine, 
carries  the  other,  through  a  deliquescent  substance,  down 
along  with  it.  It  is  obtained  pure  by  acting  on  the  sedi¬ 
ment  of  urine  with  alcohol. 

SEBACIC  ACID. 

Subject  to  a  considerable  heat  7  or  8  pounds  of  hog’s 
lard,  in  a  stone-ware  retort  capable  of  holding  double 
the  quantity,  and  connect  its  beak  by  an  adopter  with  a 
cooled  receiver.  The  condensible  products  are  chiefly 
fat,  altered  by  the  fire,  mixed  with  a  little  acetic  and 
sebacic  acids.  Treat  this  product  with  boiling  water 
several  times,  agitating  the  liquor,  allowing  it  to  cool,  and 
decanting  each  time.  Pour  at  last  into  the  watery  liquid, 
solution  of  acetate  of  lead  in  excess.  A  white  flocculent 
precipitate  of  sebate  of  lead  will  instantly  fall,  which 
must  be  collected  on  a  filter,  washed  and  dried.  Put  the 
17  ,  N 


CHEMISTRY. 


194 

sebate  of  lead  into  a  phial,  and  pour  upon  it  its  own 
weight  of  sulphuric  acid,  diluted  with  five  or  six  times 
its  own  weight  of  water.  Expose  this  phial  to  the  heat 
of  about  512°.  The  sulphuric  acid  combines  with  the 
oxide  of  lead,  and  sets  the  sebacid  acid  at  liberty.  Filter 
the  whole  while  hot.  As  the  liquid  cools,  the  sebacid 
acid  crystallizes,  which  must  be  washed,  to  free  it  from 
the  adhering  sulphuric  acid.  Let  it  then  be  dried  at  a 
gentle  heat. 

The  sebacid  acid  is  inodorous;  its  taste  is  slight,  but 
it  perceptibly  reddens  litmus  paper ;  its  specific  gravity 
is  above  that  of  water,  and  its'  crystals  are  small  white 
needles  of  little  coherence.  Exposed  to  heat,  it  melts 
like  fat,  is  decomposed,  and  partially  evaporated.  The 
air  has  no  effect  upon  it.  It  is  much  more  soluble  in  hot 
than  in  cold  water ;  hence  boiling  water  saturated  with 
it,  assumes  a  nearly  solid  consistence  on  cooling.  Alco¬ 
hol  dissolves  it  abundantly  at  the  common  temperature. 

With  the  alkalies  it  forms  soluble  neutral  salts:  but 
if  we  pour  into  them  concentrated  solutions,  sulphuric, 
nitric,  or  muriatic  acids,  the  sebacic  is  immediately 
deposited  in  large  quantity.  It  affords  precipitates  with 
the  acetates  and  nitrates  of  lead,  mercury,  and  silver. 

Such  is  the  account  given  by  Thenard  of  this  acid. 

SELINIC  ACID. 

If  selinium  be  heated  to  dryness,  it  forms,  with  nitric 
acid,  a  volatile  and  crystallizable  compound,  called  se- 
linic  acid,  which  unites  to  some  of  the  metallic  oxides, 
producing  salts  called  seleniates. 

SORBIC  ACID. 

From  sorbus,  the  mountain-ash,  from  the  berries  of 
which  it  is  obtained.  The  acid  of  apples,  called  malic, 
mav  be  obtained  most  conveniently,  and  in  the  greatest 
purity,  from  the  berries  of  the  mountain-ash,  called  sor¬ 
bus,  or  pyrus  aucuparia  ;  and  hence,  the  present  name. 


SORBIC  ACID. 


195 

sorbic  acid.  This  was  supposed  to  be  a  new  and  pecu¬ 
liar  acid  by  Donovan  and  Vanquelin,  who  wrote  good 
dissertations  upon  it.  But  it  now  appears,  that  the  sorbic 
and  pure  malic  acids  are  identical. 

Bruise  the  ripe  berries  in  a  mortar,  and  then  squeeze 
them  in  a  linen  bag.  They  yield  nearly  half  their 
weight  of  juice,  of  the  specific  gravity  of  1.077.  This 
viscid  juice,  by  remaining  for  about  a  fortnight  in  a 
warm  temperature,  experiences  the  vinous  fermenta¬ 
tion,  and  would  yield  a  portion  of  alcohol.  By  this 
change,  it  has  become  bright,  clear,  and  passes  easily 
through  the  filter,  while  the  sor  bic  acid  itself  is  not  al¬ 
tered.  Mix  the  clean  juice  with  a  filtered  solution  of 
acetate  of  lead,  separate  the  precipitate  on  a  filter,  and 
wash  it  with  cold  water.  A  large  quantity  of  boiling 
water  is  then  to  be  poured  upon  the  tiller,  and  allowed 
to  drain  in  glass  jars.  At  the  end  of  some  hours,  the 
solution  deposits  crystals  of  great  lustre  and  beautv 
Wash  these  with  cold  water,  dissolve  them  in  boiling 
water,  filter,  and  crystallize.  Collect  the  new  crystals, 
and  boil  them  for  half  an  hour  in  two  or  three  times 
their  weight  of  sulphuric  acid,  specific  gravity  of  1.090, 
supplying  water  as  fast  as  it  evaporates,  and  stirring 
the  mixture  diligently  with  a  glass  rod.  The  clear 
liquor  is  to  be  decanted  into  a  tall,  narrow  glass  jar, 
and,  while  still  hot,  a  stream  of  sulphuretted  hydrogen 
is  to  be  passed  through  it.  When  the  lead  has  been  all 
thrown  down  in  a  sulphuret,  the  liquor  is  to  be  filtered, 
and  then  boiled  in  an  open  vessel,  to  dissipate  the  ad¬ 
hering  sulphuretted  hydrogen.  It  is  now  a  solution  of 
sorbic  acid.  When  it  is  evaporated  to  the  consistence 
of  a  syrup,  it  forms  mamelated  masses,  of  a  crystalline 
structure.  It  still  contains  considerable  water,  and  de¬ 
liquesces  when  exposed  to  the  air.  Its  solution  is  trans¬ 
parent,  colourless,  void  of  smell,  but  powerfully  acid  to 
the  taste.  Lime  and  barytes  waters  are  not  precipitated 
by  solution  ot  the  sorbic  acid,  although  the  sorbate  of 
lime  is  nearly  insoluble.  One  of  the  most  characteristic 
properties  of  this  acid  is  the  precipitate  which  it  gives 


CHEMISTRY. 


19  G 

with  the  acetate  of  lead,  which  is  at  first  white  and 
flocculent,  but  afterwards  assumes  a  brilliant,  crystal¬ 
line  appearance.  With  potassa,  soda,  and  ammonia, 
it  forms  crystallizable  salts,  containing  an  excess  of  acid. 

STANNIC  ACID. 

A  name  which  has  been  given  to  the  peroxide  of  tin, 
because  it  is  soluble  in  alkalies. 

SUCCINIC  ACID. 

This  acid  is  obtained  from  amber,  which  is  a  brown, 
transparent,  combustible  substance,  dug  out  of  the 
earth,  in  some  countries,  and  found  upon  the  sea-coast, 

in  others.  .  .  . 

During  the  distillation  of  amber,  the  crystals  of  this 

acid  attach  themselves  to  the  neck  of  the  retort.  They 
were  formerly  called  salt  of  amber.  When  puiilied 
by  repeated  solution  in  hot  water,  Alteration,  and  re¬ 
crystallization,  they  are  white,  shining,  triangular  prisms. 
Their  taste  is  slightly  acid :  they  redden  tincture  of  lit¬ 
mus,  but  have  no  effect  on  syrup  of  violets. 

This  acid  obtains  its  name  from  succinum ,  the  Latin 
name  of  amber.  Its  salts  are  called  succinates.- 


SUBERIC  ACID. 

This  acid  exists  in  cork.  It  is  obtained  by  distilling 
nitric  acid  of  cork  grated  to  powder,  till  the  cork  ac¬ 
quires  the  consistence  of  a  wax,  and  no  more  red  fumes 
appear.  The  residuum  is  placed  in  a  sand-heat,  and 
continually  stirred,  till  white  penetrating  vapours  appear. 
It  is  then  removed  from  the  sand-heat,  and  stirred  till 
cold.  Boiling  water  is  poured  upon  the  product;  heat 
is  applied  till  it  liquifies,  and  it  is  then  filtered.  A  sedi¬ 
ment  is  deposited,  which  must  be  separated  by  the  filter, 
and  the  fluid  evaporated  nearly  to  dryness.  The  mass 
thus  obtained  is  the  suberic  acid.  It  may  be  further 


SULPHURIC  ACID. 


197 


purified  by  saturating  it  with  potass,  and  precipitating  it 
by  means  of  an  acid ;  or  by  boiling  it  along  with  char 
coal  powder. 

Suberic  acid  is  not  crystallizable ;  boiling  water  dis¬ 
solves  half  its  weight  of  it,  but  it  is  nearly  insoluble  in 
cold  water.  Its  taste  is  acid,  and  slightly  bitter.  It 
reddens  most  vegetable  blues,  but  has  the  peculiar  prop¬ 
erty  of  changing  the  solution  of  indigo  in  sulphuric  acid 
to  a  green. 

It  attracts  moisture  from  the  atmosphere,  and  exposure 
to  light  renders  it  brown.  It  has  no  action  on  gold  oi 
nickel,  but  oxidixes  most  of  the  other  metals.  With 
different  bases,  its  salts  are  called  suberates. 

SULPHURIC  ACID. 

Sulphuric  acid  is  the  union  of  oxygen  and  sulphur,  in 
which  the  proportion  of  sulphur  is,  according  to  Berthollet, 
G3.2,  and  that  of  oxygen  3G.8. 

Sulphuric  acid  is  strongly  corrosive  and  destitute  of 
colour  and  smell.  It  may  be  rendered  twice  the  weight 
of  water,  but  its  customary  specific  gravity  seldom  ex¬ 
ceeds  1.8.  When  concentrated  only  to  1.7,  it  will  freeze 
sooner  than  water,  but  not  if  either  more  or  less  concen¬ 
trated.  This  was  discovered  by  Keir.  Sulphuric  acid 
is  so  intensely  acidulous,  that  though  diluted  with  7000 
times  its  weight  of  water,  its  taste  is  still  distinguishable. 

Sulphuric  acid  was  formerly  procured  by  distillation 
from  the  salt  which,  previous  to  the  adoption  of  the  new 
nomenclature,  was  called  green  vitriol ;  on  this  account, 
and  its  having  in  some  measure  an  oily  consistence,  it 
was  called  oil  of  vitriol.  At  present,  it  is  furnished  for 
the  demand  of  trade,  by  burning  sulphur  in  close  cham¬ 
bers,  with  the  addition  of  nitrate  of  potass  to  supply 
oxygen.  The  floor  of  the  chamber  is  covered  by  a 
leaden  cistern,  containing  water,  by  which  the  vapours 
of  the  sulphur  are  attracted  and  condensed.  This  pro¬ 
cess  does  not  furnish  the  acid  in  a  state  of  purity  ;  but 
at  least  communicates  to  it  some  of  the  foreign  substances 
’ead  and  potass.  It  is  purified  by  distillation. 

17  * 


CHEMISTRY . 


198 

Sulphuric  acid  speedily  destroys  the  texture  of  animal 
and  vegetable  substances;  it  changes  all  vegetable  blues 
to  red,  with  the  exception  of  indigo.  It  has  a  strong 
attraction  for  water,  of  which  Neuman  asserts  it  will 
abstract  from  the  atmosphere  6.25  of  its  own  weight. 

When  sulphuric  acid  is  mixed  with  water,  much  ca 
loric  is  evolved,  and  the  specific  gravity  of  the  compound 
is  greater  than  intermediate.  The  mixture  of  four 
pounds  of  acid,  with  one  of  water,  will  raise  the  ther 
mometer  to  300°. 

Sulphuric  acid  decomposes  alcohol  and  the  oils;  when 
assisted  by  heat,  it  decomposes  most  of  the  metallic 
oxides,  and  most  readily  those  which  contain  the  greatest 
quantity  of  oxygen,  as  the  red  oxide  of  lead,  the  black 
oxide  of  manganese. 

It  oxidizes  iron,  zinc,  and  manganese  in  the  cold. 
Assisted  by  heat,  it  oxidizes  silver,  mercury,  copper, 
antimony,  bismuth,  arsenic,  tin,  and  tellurium.  At  a 
boiling  heat,  it  oxidizes  lead,  cobalt,  nickel,  and  molybde¬ 
num.  It  has  no  action  upon  gold,  platina,  tungsten,  or 
titanium. 

It  unites  readily  with  all  the  alkalies,  and  alkaline 
earths,  also  with  alumine,  and  zircon  ;  with  which,  and 
most  of  the  metallic  oxides,  it  forms  salts,  which  are 
called  sulphates;  thus  sulphate  of  potass,  formerly  called 
vitriolated  tartar,  is  a  combination  of  the  sulphuric  acid 
and  potass,  and  sulphate  of  soda  (Glauber’s  salts,)  is  a 
combination  of  sulphuric  acid  and  soda. 

SULPHUROUS  ACID. 

If  sulphuric  acid  be  deprived  of  part  of  its  oxygen,  it 
is  converted  into  sulphurous  acid;  but  the  quantity  of 
oxygen  which  must  be  abstracted  to  ctlect  this  change 
or,  in  other  words,  the  quantity  of  oxygen  which  is  con¬ 
tained  in  sulphurous  acid,  has  never  been  ascertained. 

Sulphurous  acid  is  the  result  of  a  very  slow  combus¬ 
tion  of  sulphur ;  whereas,  in  a  rapid  combustion,  the 
sulphur  combines  with  more  oxygen,  and  forms  sulphuric 
ncid. 


TARTARIC  ACID. 


19;> 

It  is  usually  procured  by  mixing,  with  sulphuric  acid, 
oil,  grease,  metals,  or  any  other  substance  that  has  a 
stronger  affinity  for  oxygen  than  sulphuric  acid,  and  pro¬ 
ceeding  to  distillation.  Sugar  is  one  of  the  best  substances 
which  can  be  employed.  By  this  means,  the  acid  may 
be  obtained  in  a  gaseous  form,  in  which  state  it  is  colour¬ 
less  and  invisible,  like  common  air,  exhales  the  odour  of 
burning  sulphur,  and  cannot  be  breathed  without  suffo¬ 
cation.  Extreme  cold  converts  it  into  a  liquid.  When 
combined  with  water,  for  which  it  has  a  strong  attrac¬ 
tion,  it  does  not  entirely  lose  its  smell  like  sulphuric 
acid. 

Blue  vegetable  colours  are  reddened  by  sulphurous 
acid,  previous  to  their  being  discharged. 

This  acid  does  not  oxidize  so  many  of  the  metals  as 
sulphuric  acid.  The  metals  upon  which  it  has  this  effect, 
appear  to  be  only  iron,  zinc,  and  manganese. 

With  the  alkalies,  alkaline  earths,  alumine,  and  some 
of  the  metallic  oxides,  it  forms  the  salts  called  sulphites. 

TARTARIC  ACID. 

A  hard  substance  is  found  adhering  to  the  sides  of 
casks  in  which  some  kinds  of  wine  have  been  fermented  : 
this  substance  is  tinged  with  the  colour  of  the  wine ;  but, 
when  it  has  been  purified  by  solution,  Alteration,  and 
crystallization,  it  constitutes  the  salt  called  cream  of 
tartar.  Cream  of  tartar  consists  of  potass,  united  to  a 
peculiar  acid :  this  acid  is  tartaric  acid.  Cream  of  tar¬ 
tar  is  supertartrate  of  potass. 

To  obtain  tartaric  acid,  four  parts  of  supertartrate  of 
potass  may  be  boiled  in  twenty  parts  of  water,  and  one 
part  of  sulphuric  acid  added  gradually.  By  continuing 
the  boiling,  the  sulphate  of  potass  will  fall  down.  When 
the  liquor  is  reduced  to  one-half,  it  is  to  be  filtered,  and 
if  any  more  sulphate  be  deposited  by  continuing  the  boil¬ 
ing,  the  filtering  must  be  repeated.  When  no  more  is 
thrown  down,  the  liquor  is  to  be  evaporated  to  a  syrup; 
and  thus  crystals  of  tartaric  acid  equal  to  half  the  weigh! 


CHEMISTRY. 


200 

of  the  tartar  employed,  will  be  obtained.  These  crys¬ 
tals  readily  dissolve  in  water,  and  the  solution  crystallizes 
by  evaporation. 

The  tartaric  acid  does  not  oxidize  platina,  gold,  silver 
lead,  bismuth  or  tin  ;  and  its  action  on  antimony  and 
nickel  is  very  slight.  It  unites  with  the  alkalies,  and  most 
of  the  earths.  The  salts  formed  with  it  are  called  tar¬ 
trates.  . 

The  supertartrate  of  potass,  from  which  this  acid  is 
obtained,  is  much  used  in  medicine;  it  is  cooling,  and 
gently  aperient :  in  domestic  economy,  it  is  dissolved  in 
water,  and,  with  the  addition  of  a  little  sugar  and  a  few 
slices  of  lemon,  forms,  after  standing  a  day  or  two,  an 
agreeable  beverage,  called  imperial  water.  An  infusion 
of  green  balm,  instead  of  water,  improves  this  liquor. 

Mixed  with  an  equal  weight  of  nitre,  and  thrown  into 
a  red  hot  crucible,  supertartrate  of  potass  detonates, 
and  forms  the  while  jlux ;  with  half  its  weight  of  nilie, 
it  forms  the  black  Jlux ;  and  by  simple  mixture  with 
nitre  in  various  proportions,  it  is  called  raw  Jlux.  It  is, 
likewise,  used  in  dyeing,  gilding,  whitening  pins,  and  other 
arts. 

TELLIRIC  ACID. 

The  oxide  of  tellurium  combines  with  many  of  the 
metallic  oxides,  acting  the  part  of  an  acid,  and  produ¬ 
cing  a  class  of  compounds  which  have  been  called  tcllu- 
rates. 

TUNGSTIC  ACID. 

This  acid  has  been  found  only  in  two  minerals ;  one 
of  which,  formerly  called  tungsten,  is  a  tungstate  of 
lime,  and  is  very  rare;  and  the  other,  more  common,  is 
composed  of  tungstic  acid,  oxide  of  iron,  and  a  little 
oxide  of  manganese.  The  acid  is  separated  from  the 
latter  in  the  following  way: — The  wolfram,  cleared  trom 
its  silicious  gangue,  and  pulverized,  is  heated  in  a  mat- 
trass,  with  live  or  six  times  its  weight  ot  muriatic  acid, 
'or  half  an  hour.  The  oxides  of  iron  and  manganese 


TUNGSTOUS  ACID,  ZUMIC  ACID,  ZOONIC  ACID.  201 

'being  thus  dissolved,  we  obtain  tungstic  acid  in  the  form 
of  a  yellow  powder.  Alter  washing  it  repeatedly  with 
water,  it  is  then  digested  in  an  excess  of  liquid  ammonia, 
heated,  which  dissolves  it  completely.  The  liquor  is 
filtered  and  evaporated  to  dryness  in  a  capsule.  The 
dry  residue  being  ignited,  the  ammonia  flies  off,  and  pure 
tungstic  acid  remains.  If  the  whole  of  the  wolfram  has 
not  been  decomposed  in  this  operation,  it  must  be  sub¬ 
jected  to  the  muriatic  acid  again. 

It  is  tasteless,  and  does  not  a  fleet  vegetable  colours. 
The  tungstates  of  the  alkalies  and  magnesia  are  soluble 
and  crystallizable,  the  other  earthy  ones  are  insoluble,  as 
well  as  those  of  the  metallic  oxides.  The  acid  is  com¬ 
posed  of  100  parts  pure  metallic  tungsten,  and  25  or  26.4 
oxygen. 

TUNGSTOUS  ACID. 


What  has  been  thus  called  appears  to  be  an  oxide  of 
tungsten. 


ZUMIC  ACID. 


Ax  acid  produced  from  vegetable  substances,  which 
have  undergone  acetous  fermentation.  Its  claim  to  be 
considered  as  a  distinct  compound  is  doubtful.  (See 
JVuncic  Acid.) 

ZOONIC  ACID. 


In  the  liquid  procured  by  distillation  from  animal  sub¬ 
stances,  which  had  been  supposed  only  to  contain  car¬ 
bonate  of  ammonia  and  an  oil,  Berthollet  imagined  he 
had  discovered  a  peculiar  acid,  to  which  he  gave  the 
name  of  zoonic.  Thenard  has  demonstrated,  however, 
that  it  is  merely  acetic  acid  combined  with  animal 
matter. 


202 


CHEMISTRY. 


OF  ALKALIES. 

Alkalies  are  possessed  of  the  following  properties: 

1.  They  are  soluble  in  water  ;  2.  they  have  an  acrid 
and  urinous  taste;  3.  they  are  incombustible;  4.  they 
change  most  vegetable  blues  to  green,  and  the  yellow  to 
a  brown ;  5.  they  form  neutral  salts  with  acids ;  G.  they 
render  oils  miscible  with  water. 

Potass  and  soda  are  called  fixed  alkalies,  because  they 
are  not  volatilized  except  by  an  intense  heat;  ammonia 
is  called  the  volatile  alkali,  because  it  is  dissipated  or 
converted  into  gas  at  a  moderate  heat. 

Oxygen  is  a  compound  part  of  all  the  alkalies,  and 
appears  clearly  in  the  case  of  two  fixed  alkalies,  to  be 
the  alkalizing  principle.  The  bases  of  the  alkalies  are 
metals. 

Table  of  saline  products  of  one  thousand  pounds  of 
ashes  of  the  following  vegetables : 

SALINE  PRODUCTS. 

Stalks  of  Turkey  wheat  or  maize,  198  lbs. 


Stalks  of  sun-flower,  -  -  -  -  349  “ 

Vine  branches, . 1G2.6  “ 

Elm, . 1GG  « 

Box, . 78  “ 

Sallow, . 102  “ 

Oak, . Ill  “ 

Aspen,  --------  61  “ 

Beech, . 219  “ 

Fir, . 132  “ 

Fern  cut  in  August,  -  -  -  -  117  “ 

Wormwood,  ------  748  “ 

Fumitory,  -------  3G0  “ 

Heath,  - . 115  u 


POTASS. 


203 


POTASS. 

If  (he  ashes  of  burnt  vegetables  be  repeatedly  lixi* 
viated,  until  they  cease  to  communicate  any  taste  to  the 
water,  and  the  water  be  evaporated  to  dryness,  a 
saline  residue  is  obtained,  which  in  commerce  is  known 
by  the  name  of  potash.  It  has  been  called  the  vegetable 
alkali,  because  it  was  supposed  to  be  furnished  bv  vege¬ 
tables  only.  J  b 

Potash  contains  a  number  of  foreign  salts,  and  other 
impurities;  but  when  deprived  of  all  these,  it  is  called 
by  chemists  potass. 

Pure  potass  is  extremely  white,  and  so  caustic,  that  if 
applied  to  the  hand,  the  skin  is  instantly  destroyed;  it  is 
therefore  in  this  state  called  caustic  alkali. 

The  potash  of  commerce  is  always  combined  with 
carbonic  acid,  for  which  it  has  a  strong  affinity,  and  it  is 
this  addition  which  disguises  its  properties  more  than  all 
the  rest,  and  reduces  it  to  its  usual  state  of  what  is 
called  mild  alkali,  or  by  chemists  carbonate  of  potass, 
or  rather  sub-carbonate  of  potass,  as  it  is  not  saturated 
with  the  carbonic  acid. 

If  potash  be  dissolved  in  water,  and  mixed  with  an 
equal  quantity  of  quick-lime  made  into  a  paste  with  the 
same  fluid,  the  lime  having  a  greater  affinity  for  the 
carbonic  acid  than  the  potass,  will  combine  with  it;  the 
potash  remains  in  solution,  and  may  be  separated  from 
the  lime  by  Alteration.  The  evaporation  of  this  solution 
should  be  performed  in  close  vessels,  otherwise  the  potass 
will  abstract  carbonic  acid  from  the  air. 

Potass  is  soluble  in  its  weight  of  water.  It  attracts 
moisture  from  the  gases  with  avidity ;  and,  therefore, 
affords  the  means  of  drying  them.  It  is  soluble,  also,  in 
alcohol,  which  is  not  the  case  when  it  is  in  a  state  of 
carbonate. 

By  exposure  to  heat,  potass  becomes  soft ;  and  at  the 
commencement  of  ignition,  it  melts  into  a  transparent 
glass ;  by  increasing  the  heat,  it  is  volatilized. 

Potass  and  silex,  when  fused  together  in  equal  quan- 


CHEMISTRY. 


204 

ties,  combine,  and  form  glass.  If  the  proportion  of  po¬ 
tass  to  that  of  silex  be  as  three  or  four  to  one,  the  glass 
will  be  soft  and  soluble  in  water.  This  composition  is 
called  siliceous  potass,  or  liquor  of  flints. 

If  a  solution  of  potass  be  boiled  upon  silex  recently 
procured,  it  dissolves  a  part  of  it.  As  the  solution  cools, 
it  assumes  the  appearance  of  a  jelly,  even  though  pre¬ 
viously  diluted  with  seventeen  times  its  weight  of  water. 

Potass,  combined  with  fixed  oils,  forms  soap. 

It  combines  with  sulphur,  both  in  the  dry  and  the 
humid  way,  forming  sulphuret  of  potass.  When  this 
sulphuret  is  obtained  by  the  fusion  of  its  component  parts, 
it  is  of  a  brown  colour, "soluble  in  w'ater,  and  soon  attracts 
water  from  the  atmosphere.  When  it  has  acquired 
moisture,  it  is  then  in  a  state  to  act  on  the  air,  from 
which  it  will  abstract  oxygen ;  and,  if  inclosed  with  a 
quantity  of  it  in  a  jar,  the  nitrogen  will  be  left  alone. 

Sulphuret  of  potass,  allowed  to  remain  moist  in  the 
atmosphere,  is  at  length  converted  into  sulphate  of  po¬ 
tass;  for  the  sulphur,  combining  with  oxygen,  forms  sul¬ 
phuric  acid,  and  the  water  is  decomposed,  giving  out 
sulphuretted  hydrogen  gas. 

SODA. 

Soda,  called  also  mineral,  or  fossil  alkali,  because  it 
was  considered  as  exclusively  derived  from  the  mineral 
kingdom,  is  nearly  similar  to  potass  in  its  properties. 

iSoda  is  one  of  the  most  abundant  substances,  but  is 
r.*ver  met  with  naturally,  except  in  a  state  of  combina¬ 
tion.  It  forms  common  salt  when  combined  with  mu¬ 
riatic  acid,  and  this  acid  is,  therefore,  called  muriate  of 
soda.  Hence,  those  inexhaustible  mines  of  salt  which 
are  found  in  England,  Poland,  and  other  countries,  and 
even  the  ocean  itself,  which  holds  it  in  solution,  are  so 
many  vast  depositaries  of  soda. 

The  French  chemists  have  attempted  to  obtain  muri 
atic  acid  and  soda,  by  the  decomposition  of  sea-salt,  but 
the  process  is  too  expensive  for  general  use.  The  soda 


SODA. 


205 


of  commerce  is  therefore  obtained  from  the  ashes  of 
marine  plants,  and  from  one  of  these  (the  salsola  soda ' 
it  derives  its  name.  In  Scotland,  this  and  other  sea¬ 
weeds  are  collected,  dried,  and  burned  in  pits  dug  in  the 
sand,  or  in  heaps  surrounded  by  loose  stones.  Fresh 
quantities  are  added,  as  the  first  are  consumed,  and  a 
hard  residuum  is  obtained,  which  is  of  a  black  or  bluish 
colour;  it  is  called  kelp,  and  contains  from  2k  to  3  per 
cent  of  soda.  On  the  coasts  of  France  and  Spain  the 
same  kind  of  manufacture  is  carried  on,  and  the  produce 
-  is  called  barilla.  The  barilla  of  Alicant  is  much  noted. 

Soda  is  obtained  from  kelp  and  barilla  by  lixiviation, 
Alteration,  and  crystallization.  These  processes  leave  it 
in  the  state  of  a  carbonate,  but  it  may  be  deprived  of 
its  carbonic  acid,  and  rendered  caustic,  by  lime,  in  the 
same  manner  as  potass. 

Potass  and  soda,  in  a  state  of  purity,  cannot  be  distin¬ 
guished  bv  inspection  from  each  other.  The  oxalic  acid 
has  been  used  as  a  test  to  distinguish  them.  I  his  acid, 
with  potass,  forms  a  very  soluble  salt,  but  with  soda  one 
of  difficult  solubility.  A  solution  of  the  ore  of  platina 
in  nitro-muriatic  acid,  also  affords  the  means  of  dis¬ 
tinguishing  them ;  for  the  solution  of  potass  will  form  a 
yellow  precipitate,  but  soda  gives  no  precipitate. 

Fourcroy  suggests  that  soda  is  the  most  proper  of  the 
two  fixed  alkalies  to  be  employed  in  medicine  ;  because 
animal  substances  always  contain  it,  but  they  never  con¬ 
tain  potass. 

If  potass  be  exposed  to  the  atmosphere,  it  deliquesces, 
that  is,  acquires  moisture ;  if  soda  be  exposed  in  the 
same  manner,  it  effloresces,  that  is,  parts  with  moisture, 
and  is  converted  into  a  dry  powder. 

Soda  is  preferred  to  potass  in  most  manufactures,  its 
affinities  in  general  are  not  so  strong  as  those  of  potass, 
it  is  therefore  less  corrosive.  It  is  more  fusible  alone, 
and  fuses  silex  more  readily  than  potass,  hence  it  is  em¬ 
ployed  in  manufacture  of  glass. 

Carbonic  acid  renders  soda,  as  well  as  potass,  fit  for 
many  purposes  to  which,  in  its  caustic  state,  it  would 
18 


206 


CHEMISTRY. 


not  be  applicable.  It  is  in  this  state  that  these  alkalies 
are  employed,  in  medicine,  and  in  washing  linen. 

The  combination  of  potass  or  soda  with  oil  or  tallow, 
forms  soap;  but  soda  forms  hard  soap,  while  potass  only 
affords  soft  soap.  Soda  is  therefore  much  more  valuable, 
and  generally  used  in  the  manufacture  of  soap,  for  which 
use  it  is  rendered  caustic,  by  quick-lime.  Muriate  of 
soda  is  added  in  making  soap,  in  order  to  harden  it.  The 
brown  or  yellow  soap  contains  a  quantity  of  rosin.  Black 
or  green  soft  soap  is  made  with  the  coarsest  oils,  and 
retains  all  its  alkaline  ley. 

The  weakest  acids  have  the  power  of  decomposing 
soap,  because  they  have  a  stronger  affinity  for  its  alkali 
than  the  oil.  Soap  is  also  decomposed  by  metallic  oxides, 
earths,  and  neutral  salts.  Hence  the  water  of  springs 
is  said  to  be  hard,  because  soap  is  not  soluble  in  it,  or 
rather  is  not  decomposed  by  it.  Solution  of  soap  may 
therefore  be  employed  to  show  whether  water  holds  min 
erals  in  solution  or  not. 

AMMONIA. 

If  muriate  of  ammonia,  in  powder,  be  mixed  with 
three  parts  of  slacked  lime,  and  distilled,  and  the  pro¬ 
duct  be  collected  by  the  mercurial  trough,  or  pneumatic 
apparatus,  a  gas  is  obtained,  which  is  transparent  and 
colourless,  like  common  air.  This  gas  is  called  ammoni - 
acal  gas,  and  is  the  purest  state  in  which  ammonia  can 
ne  exhibited. 

Ammonia  has  a  pungent,  though  not  unpleasant  smell. 
Its  taste  is  acrid  and  caustic,  like  that  of  the  fixed  alka¬ 
lies,  but  not  so  strong  ;  nor  has  it  the  property,  like  them, 
of  corroding  animal  substances.  It  is  not  respirable. 
Its  specific  gravity  to  common  air  is  as  3  to  5.  When 
exposed  to  a  cold  of  45°,  it  is  condensed  in  a  liquid,  which 
again  assumes  the  gaseous  form,  when  the  temperature 
is  raised. 

Ammonia  is  rapidly  absorbed  by  water,  and  the  absorp¬ 
tion  goes  on  till  the  water  has  acquired  more  than  a 


AMMONIA. 


207 


third  of  its  weight  of  it.  It  therefore  instantly  disappears 
if  water  be  introduced  into  a  jar  of  it;  some  caloric  is 
evolved,  and  the  specific  gravity  of  the  water  is  dimin¬ 
ished.  If  ice  be  introduced  into  this  gas,  it  melts  and 
absorbs  the  ammonia,  while  at  the  same  time  its  tempera¬ 
ture  is  dimished.  The  specific  gravity  of  water  saturated 
with  ammonia,  at  00°  is  9054.  It  is  the  attraction  of 
water  for  ammonia,  which  renders  it  necessary  to  em¬ 
ploy  mercury  in  obtaining  the  gas. 

Water  combined  with  ammonia,  acquires  its  smell, 
and  has  a  disagreeable  taste ;  it  converts  vegetable  blues 
to  green.  It  is  this  liquid  solution  of  ammonia  which  is 
meant  in  speaking  of  the  volatile  alkali.  When  heated 
to  the  temperature  of  130°,  the  ammonia  separates  in 
the  form  of  gas.  When  its  temperature  is  reduced  to 
46°,  it  crystallizes ;  and  when  suddenly  cooled  down  to 
68°,  it  assumes  the  appearance  of  a  thick  jelly,  and  has 
scarcely  any  smell. 

Ammonia  may  be  obtained  by  the  dry  distillation  of 
bones  and  other  animal  matters  ;  it  is  from  such  substan¬ 
ces  that  it  is  obtained  to  supply  the  demand  of  commerce, 
and  it  is  sold  under  the  name  of  spirits  of  hartshorn. 
The  product  of  the  first  distillation  from  bones,  &c.  is 
very  impure:  it  is  therefore  improved  by  repeated  dis¬ 
tillations. 

Berthollet’s  experiments  evince  that  one  thousand 
parts  of  ammonia  consist  of  807  parts  of  nitrogen,  and 
193  parts  of  hydrogen ;  Sir  H.  Davy  having  discovered 
oxygen  to  be  the  alkalizing  principle  in  potass  and  soda, 
was  convinced  of  the  probability  of  its  existing  in  am¬ 
monia.  His  researches  confirmed  this  opinion,  and  he 
concludes  the  proportion  of  oxygen  in  ammonia  to  be  at 
least  7  or  8  per  cent.  He  also  succeeded  in  separating 
from  it  a  substance  of  a  metallic  nature.  The  ammonia 
was  decomposed  by  galvanism  in  contact  with  mercury. 
The  mercury,  by  combining  with  about  one  twelve-thou¬ 
sandth  part  of  this  new  matter,  has  its  identity  destroyed; 
it  becomes  solid,  and  its  specific  gravity  is  reduced  from 
13.5  to  less  than  3.0,  but  its  colour,  lustre,  opacity,  and 


CHEMISTRY. 


208 

conducting  powers  remain.  The  difficulty  of  obtaining 
and  operating  upon  this  substance,  has  hitherto  prevented 
its  being  sufficiently  known  to  assign  its  proper  place  in 
the  classification  of  bodies. 

Ammonial  gas  has  no  effect  upon  sulphur  or  phosphorus. 
Charcoal  absorbs  it,  without  altering  its  properties  when 
cold  ;  but  when  the  gas  is  made  to  pass  through  red-not 
charcoal,  part  of  the  charcoal  combines  with  it,  an 
forms  prussic  acid. 

The  two  gaseous  substances,  ammonia  and  muriatic 
acid,  combine  rapidly,  and  form  the  solid  substance  called 
muriate  of  ammonia,  which  is  the  sal-ammoniac  of  com¬ 
merce.  This  is  one  of  the  most  remarkable  and  curious 
facts :  separately,  ammonia  and  muriatic  acid  gas  are 
two  of  the  most  pungent  and  volatile  substances  known  ; 
in  union  they  are  hard,  inodorous,  not  volatile,  and  possess 
but  little  taste. 

Muriate  of  ammonia  was  formerly  supplied  by  Egypt, 
but  it  is  now  made  in  other  couiffries  (England  for  in¬ 
stance)  from  soot. 

Ammonia  combines  with  oils,  and  forms  soap ;  it  does 
not  combine  with  the  metals,  but  it  changes  some  of 
them  into  oxides,  and  then  dissolves  them.  Liquid  am¬ 
monia  is  capable  of  dissolving  the  oxides  of  silver,  copper, 
iron,  tin,  nickel,  zinc,  bismuth,  and  cobalt.  Its  use  in 
medicine  is  considerable. 

PEARL-ASH. 

An  impure  potassa  obtained  by  lixiviation  from  the 
nshes  of  plants. 


See  Potass 


POTASH. 


SALTS. 


209 


OF  SALTS. 

The  compound  formed  by  the  combination  of  an  acid 
with  an  alkali,  an  earth,  or  a  metallic  oxide,  is  called  a 
salt. 

The  term  neutral  salt,  was  formerly  given  to  all  com 
binations  of  acids  and  alkalies,  but  the  epithet  neutral 
is  now  restricted  to  those  salts  in  which  the  acid  and  the 
alkali  completely  saturate  each  other,  and  in  which, 
therefore,  the  peculiar  properties  of  neither  can  he 
detected. 

When  a  salt  contains  an  excess  if  acid,  its  state  is 
indicated  by  the  addition  of  the  word  super ;  and  some- 
✓  times  by  the  term  acidulous;  but  the  latter  mode  of 
denoting  the  distinction,  is  yielding  to  the  former. 

When  the  salt  contains  an  excess  of  alkali,  the  pre¬ 
position  sub  is  prefixed  to  its  name,  or  the  epithet  of 
alkalinous;  but  the  first-mentioned  addition  is  the  most 
general  and  appropriate. 

The  base  or  radical  of  a  salt,  is  the  alkali,  the  earth, 
or  metallic  oxide,  which  is  combined  with  the  acid. 

Agreeably  to  the  principles  which  are  adopted  in 
forming  the  new  nomenclature,  every  salt  receives  a 
compound  name,  denoting  its  base,  and  the  acid  which 
enters  into  its  composition.  Thus,  the  chemical  name 
of  common  salt  is  muriate  of  soda,  as  it  is  a  combination 
of  muriatic  acid  and  soda.  Salt-petre  is  called  nitrate 
of  potass  ;  because  it  is  a  combination  of  potass  and  ni¬ 
tric  acid.  Glauber’s  salt  is  called  sulphate  of  soda,  as  it 
is  a  combination  of  soda  with  sulphuric  acid;  and  the 
salts  formed  by  all  other  acids  are  reduced  to  the  same 
form  of  expression. 

When  an  acid  is  combined  with  two  bases,  the  com¬ 
pound  is  called  a  triple  salt,  and  both  the  bases  are  ex¬ 
pressed  :  thus,  we  have  the  tartrate  of  potass  and  soda. 
A  single  base,  combined  with  two  acids,  is  denoted  with 
equal  precision  ;  thus,  we  have  the  nitro-muriate  of  tin 
18*  O 


210 


CHEMISTRY. 


When  the  epithet  which  distinguishes  the  acid  of  a 
salt  terminates  in  ate,  it  signifies  that  the  epithet  of  the 
acid  itself  terminates  in  ic ;  thus,  the  sulphuric  acid 
forms  sulphates.  When  the  epithet  of  the  salt  termi¬ 
nates  with  ite,  that  of  the  acid  itself  terminates  in  ous ; 
thus,  the  sulphurous  acid  forms  sulphites.  Most  of  the 
Salts  ending  in  ite,  extract  oxygen  from  the  atmosphere, 
and  are  converted  into  the  former  kind. 

The  salts  form  a  very  numerous  class  of  bodies.  Four 
crov  reckons  that  there  are  134  species;  and  the  number 
belonging  to  each  species  is  often  considerable.  There 
can  scarcelv  be  less  than  2000  distinct  salts ;  but  I  shall 
only  notice  some  of  the  most  useful. 


SULPHATES. 

The  sulphates  are  in  general  crystallizable,  have 
some  taste,  but  no  smell ;  are  precipitated  by  solution  of 
barytes,  and  afford  suiphurets  when  heated  red-hot  with 
charcoal.  They  are  numerous,  as  the  sulphuric  acid 
combines  with  all  the  alkalies,  and  nearly  all  the  earths, 
and  metallic  oxides. 

SULPHATE  OF  ALUMINE. 

Sulphate  of  alumine  is  formed  by  dissolving  alumine 
in  sulphuric  acid.  It  has  an  astringent  taste,  is  very 
soluble  in  water,  and  crystallizes  in  thin  plates,  which 
have  very  little  consistence.  It  generally  contains  an 
excess  of  acid. 

I  should  have  omitted  the  mention  ot  this  salt,  but  to 
distinguish  it  from  the  following  one,  to  which  the  same 
name  is  apt  to  be  given. 


SULPHATES  OF  ALUMINE  AND  SODA. 


211 


SULPHATE  OF  ALUMINE  AND  POTASS,  OR 
AMMONIA,  (ALUM.) 

This  salt  is  the  common  alum  of  commerce.  It  has 
an  austere,  sweetish,  astringent  taste,  and  always  reddens 
tincture  of  litmus.  Seventy-five  parts  of  boiling  water 
dissolve  100  of  alum,  at  the  temperature  of  60°;  it  is 
soluble  in  from  10  to  15  times  its  weight  of  cold  water, 
the  purest  alum  having  the  least  degree  of  solubility. 
Its  crystals  are  large.  I3y  exposure  to  the  air  it  slightly 
eflloresces.  Its  specific  gravity  is  1.7. 

According  to  Vanquelin,  alum  contains  of  alumine 
10.50,  sulphuric  acid  30.52,  potass  10.40,  water  48.58. 

Two  kinds  of  alum  are  found  in  commerce,  the  com¬ 
mon  and  rock  alum.  The  latter  has  a  reddish  tinge, 
from  an  admixture  of  rose-coloured  earth ;  it  is  also  the 
most  esteemed,  and  sold  at  the  greatest  price,  though  the 
cause  of  its  superiority  is  not  well  known. 

The  uses  of  alum  are  very  extensive.  In  dyeing  it  is 
of  considerable  importance  for  fixing  several  vegetable 
colours.  It  is  used  in  the  tanning  of  leather,  to  give 
firmness  to  the  skins,  after  they  have  been  in  the  lime- 
pits,  and  in  the  manufacture  of  candles,  to  give  consistence 
to  the  tallow.  Alum  may  also  be  used  to  advantage  in 
the  manufacture  of  writing-paper,  to  make  the  paper 
bear  ink  better. 

Alum  is  prepared  in  France  by  fne  artificial  combina¬ 
tion  of  its  component  parts;  but  in  Great  Britain  it  is 
obtained  from  a  kind  of  slate,  called  alum-slate,  which 
is  plentiful  on  the  north-east  coast  of  Yorkshire,  and  near 
Glasgow;  about  100  tons  of  the  slate  only  atFord  10  tons 
of  alum. 

Ammonia  will  contribute  to  the  formation  of  alum  as 
well  as  potass. 

SULPHATE  OF  SODA,  (GLAUBER’S  SALT.) 

The  sulphate  of  soda  has  a  strongly  saline  and  bitter 
taste ;  its  crystals  are  transparent,  but  they  effloresce 
and  fall  into  a  white  powder  in  the  air;  it  is  soluble  in 


CHEMISTRY. 


212 

rather  less  than  three  times  its  weight  of  water  at  the 
temperature  of  GO0,  and  in  Tyhs  of  its  weight  of  boiling 
water.  It  is  principally  used  in  medicine  as  a  purgative, 
under  the  name  ot  Glauber's  salts.  According  to  Kirwan, 
it  contains  of  acid  22  parts,  soda  17,  and  water  61. 

GREEN  SULPHATE  OF  IRON,  (COPPERAS.) 

This  salt  is  the  copperas  or  green  vitriol  of  commerce. 
Its  crystals  are  of  a  beautiful  light-green  ;  it  has  a  sharp 
astringent  taste,  and  is  poisonous.  It  is  soluble  in  6 
times  its  weight  of  water  at  the  temperature  of  60°,  and 
in  §  of  its  weight  of  boiling  water.  It  is  insoluble  in 
alcohol.  According  to  Bergman  it  contains  of  acid  39 
parts,  green  oxide  of  iron  23,  and  water  38.  It  is  efllo- 
rescent. 

Green  sulphate  of  iron  is  obtained  by  the  decomposi¬ 
tion  of  pyrites  or  native  sulphuret  of  iron  ;  and  this 
decomposition  is  effected  by  simple  exposure  to  air  and 
moisture.  This  salt  is  much  used  in  dyeing  blacks  and 
other  intermediate  colours,  both  wool  and  cotton,  also, 
for  the  black  or  iron  liquor  of  the  calico  printers ;  like¬ 
wise  in  preparing  writing  ink  ;  and  by  bookbinders  for 
staining  black  the  skins  which  have  been  tanned  with 
oak  bark. 

RED  SULPHATE  OF  IRON. 

If  nitric  acid  be  distilled  of  the  green  sulphate  of  iron, 
or  the  solution  of  this  salt  be  exposed  to  the  air,  the  red 
sulphate  of  iron  is  obtained.  It  is  deliquescent,  uncrys- 
tallizable,  and  soluble  in  alcohol.  Proust  observes  that 
it  alone  forms  prussian  blue  with  prussic  acid,  and  strikes 
a  black  colour  with  gallic  acid  ;  and  therefore,  when 
these  effects  arc  obtained  by  operating  with  the  green 
sulphate,  the  latter  salt  has  derived  from  the  atmosphere, 
or  some  other  source,  the  additional  quantity  of  oxygen 
necessary  to  convert  its  iron  to  the  state  of  red  oxide. 


SULPHATE  OF  COPPER,  NITRATE  OF  POTASS.  213 

SULPHATE  OF  COPPER,  (BLUE  VITRIOL  OR 
BLUE  COPPERAS.) 

The  crystals  of  this  salt,  which  were  formerly  called 
blue  vitriol,  are  a  fine  deep  blue.  It  has  a  strong  styptic 
taste ;  insoluble  in  four  times  its  weight  of  water,  and 
effloresces  in  the  air.  Its  specific  gravity  is  2.2.  It  is 
generally  obtained  by  evaporating  the  water  of  copper- 
mines. 

The  sulphate  of  copper  is  employed  as  a  caustic,  to 
remove  the  flesh  of  fungous  ulcers.  It  is  dangerous  to 
administer  it  internally.  It  is  also  employed  in  dyeing 
certain  colours. 


SULPHITES. 

Sulphites  have  a  disagreeable  sulphurous  taste.  If 
exposed  to  the  fire,  they  yield  sulphur,  and  are  converted 
into  sulphates,  and  even  by  mere  exposure  to  the  atmo¬ 
sphere,  the  same  change  is  produced.  They  are  also 
decomposed  by  the  nitric,  muriatic,  and  other  acids  which 
do  not  affect  sulphates.  They  are  mostly  formed  ar¬ 
tificially. 

The  principal  sulphites  are  those  of  potass,  soda, 
ammonia,  alumine,  magnesia,  and  barytes ;  none  of  these 
have  been  applied  to  purposes  ot  any  importance. 

NITRATES. 

The  nitrates  are  soluble  in  water,  and  crystallizable ; 
they  deflagrate  violently  when  heated  to  redness  with 
charcoal,  or  other  combustibles;  sulphuric  acid  disen¬ 
gages  from  them  a  white  vapour  of  nitric  acid.  By  heat 
they  are  decomposed,  and  yield  at  first  a  considerable 
quantity  of  oxygen  gas. 

NITRATE  OF  POTASS,  (SALTPETRE.) 

Nitrate  of  potass,  saltpetre,  or  nitre,  is  the  best  known 
and  most  important  of  all  the  nitrates.  Its  tast  *  jfcrwp, 


214 


CHEMISTRY. 


bitterish,  and  cooling.  It  is  very  brittle.  Its  specific 
gravity  is  1.9.  It  is  soluble  in  seven  times  its  weight  of 
cold  water,  and  in  rather  less  than  its  weight  of  boiling 
water.  When  mixed  with  one-third  of  its  weight  of 
charcoal,  and  thrown  into  a  red-hot  crucible,  or  when 
charcoal  is  thrown  upon  red-hot  nitre,  the  combustion 
that  ensues  is  exceedingly  vivid  and  beautiful.  The 
residuum  is  carbonate  of  potass.  The  combustion  is  still 
more  violent,  when  phosphorus  is  used  instead  of  char¬ 
coal. 

According  to  Kirwan,  nitre  contains  acid  41.2  parts, 
potass  46.15,  water  12.65.  All  the  nitric  acid  employed 
in  the  arts,  is  furnished  by  the  decomposition  of  this  salt. 
The  sulphuric  acid  is  employed  to  effect  the  decomposi¬ 
tion.  Considerable  quantities  of  nitre  are  also  used  in 
obtaining  sulphuric  acid,  as  it  supplies  the  oxygen  for  the 
combustion  of  sulphur  in  close  chambers.  The  manufac¬ 
ture  of  gunpowder  also  requires  an  immense  quantity. 

A  considerable  part  of  the  nitrate  of  potass  consumed 
in  Europe,  is  furnished  by  the  East  Indies,  where  the 
soil,  being  impregnated  with  it,  yields  it  by  lixiviation 
and  evaporation.  At  Apulia,  near  Naples,  also,  there  is 
a  natural  nitre-bed,  in  which  the  earth  contains  40  per 
cent,  of  nitre.  In  Germany,  France,  and  Switzerland, 
artificial  nitre-beds  are  formed,  by  sufbering  animal  and 
vegetable  matters  to  putrefy  in  combination  with  calca¬ 
reous  and  other  earths.  A  soil  of  this  kind  attracts  the 
nitric  acid  from  the  atmosphere.  Old  mortar  furnishes 
a  very  proper  calcareous  earth  for  a  nitre-bed. 

NITRATE  OF  SODA,  (CUBIC  NITRE.) 

This  salt  was  formerly  called  cubic  nitre ,  from  its 
crystallizing  rhombs.  It  is  somewhat  more  bitter  than 
the  nitrate  of  potass,  rather  more  soluble  in  cold  water, 
but  much  less  soluble  in  hot  water.  It  is  not  of  any 
important  use,  though  Proust  observes,  that  when  made 
into  gunpowder,  it  burns  longer  than  common  nitre,  and 
might  therefore  be  economically  adopted  for  fire-works. 


NITRATE  OF  AMMONIA,  MURIATES.  215 

NITRATE  OF  AMMONIA. 

Nitrate  of  ammonia  has  a  sharp,  acrid,  and  somewhat 
urinous  taste ;  it  deliquesces  in  the  air,  and  is  soluble  in 
about  half  its  weight  of  boiling  water  The  only  use 
made  of  it  is  to  furnish  nitrous  oxide. 

MURIATES. 

Though  the  muriates  are  the  most  volatile  of  the  salts, 
they  are  at  the  same  time  the  least  decomposable :  they 
may  be  melted  and  volatilized  without  undergoing  decom¬ 
position.  They  efFervesce withsulphuric  acid,  and  white 
acrid  fumes  of  muriatic  acid  are  disengaged  ;  when  acted 
upon  by  nitric  acid,  oxy muriatic  gas  is  disengaged. 

MURIATE  OF  SODA,  (COMMON  SALT.) 

Muriate  of  soda,  or  common  salt,  is  too  well  known  to 
require  any  description.  It  is  the  only  substance  to 
which  the  term  salt  was  formerly  applied.  Besides  the 
immense  quantity  of  it  held  in  solution  by  the  sea-water 
it  exists  in  prodigious  masses  in  the  state  of  rock-salt. 
Its  specific  gravity  is  2.12;  and  it  is  soluble  in  rather 
less  than  three  times  its  weight  of  water.  When  pure, 
it  is  not  affected  by  the  air ;  but  common  salt  is  deliques¬ 
cent,  from  the  magnesia  and  other  impurities  which  it 
contains. 

Muriate  of  soda  contains  of  acid  44  parts,  soda  50, 
and  of  water  6. 

MURIATE  OF  POTASS,  (SALT  OF  FEBRIFUGE.) 

This  salt  was  formerly  called  febrifuge  salt  of  Sylvius, 
and  regenerated  sea-salt.  It  has  a  disagreeable,  bitter 
taste;  its  specific  gravity  is  1.8;  it  is  soluble  in  three 
times  its  weight  of  cold  water,  and  twice  its  weight  of 
boiling  water.  When  heated,  it  first  decrepitates,  then 
melts,  and  at  last  is  volatilized  without  decomposition. 
According  to  Kirwan,  it  contains  of  acid  36  parts,  potass 
46,  and  water  18 


210 


CHEMISTRY . 


MURIATE  OF  AMMONIA,  (SAL  AMMONIAC.; 

Muriate  of  ammonia,  or  sal  ammoniac,  has  an  acrid, 
urinous  taste,  an  opaque  white  colour,  and  a  specific 
gravity  of  1.4.  It  dissolves  in  three  times  its  weight  of 
cold  water.  It  contains,  according  to  Kirwan,  35  parts 
of  acid,  30  of  ammonia,  and  35  of  water. 

Muriate  of  ammonia  is  employed  for  brightening  some 
colours  in  dyeing  and  mixing  of  colours  ;  also  for  pre¬ 
serving  the  surfaces  of  metals  from  oxidation  in  tinning; 
in  medicine  it  forms  an  excellent  diaphoretic  and  febrifuge, 
and  has  been  advantageously  applied  externally  as  a 
lotion  for  indolent  tumours. 

HYPER-OXYMURIATE  OF  POTASS. 

♦ 

If  a  solution  of  potass  be  saturated  with  oxymuriatic 
acid  gas,  and  then  evaporated  in  the  dark,  the  first 
crystals  formed  are  those  of  common  muriate  of  potass; 
when  these  are  separated,  and  the  solution  allowed  to 
cool,  the  crystals  of  the  hyper-oxymuriate  of  potass  are 
obtained.  These  crystals  have  a  silvery  lustre,  and  are 
insipid  and  cool  to  the  taste.  They  are  soluble  in  17 
parts  of  cold  water,  and  2\  of  boiling  water. 

The  hyper-oxymuriate  of  potass,  when  mixed  with 
charcoal  and  other  combustibles,  and  heated,  detonates 
with  extreme  violence.  It  also  explodes  when  triturated 
in  a  mortar,  or  when  struck  with  a  hammer,  if  a  small 
quantity  of  it  is  laid  upon  an  anvil. 

This  salt  consists  of  hyper-oxymuriatic  acid  58  parts, 
potass  39,  water  3.  The  oxygen  is  about  equal  to  the 
salt  in  weight.  It  was  called  simply  oxymuriate  of  potass 
till  Chenevix  proved  that  the  acid  which  enters  into  its 
•  composition  is  in  the  highest  state  of  oxygcnizement. 
lie  endeavoured  to  obtain  this  acid  separately,  but  the 
retort  containing  the  salt  was  reduced  almost  to  powder 
by  a  violent  explosion.  The  hyper-oxymuriatic  acid  has 
therefore  never  been  exhibited  separately. 


CARBONATES,  FLUATES. 


217 


CARBOMT  ES. 

Carbonates  effervesce  and  yield  carbonic  acid,  when 
sulphuric  or  nitric  acid  is  poured  upon  them;  all  the 
alkaline  carbonates  are  soluble  in  water,  while  those  of 
the  earths  and  metals  are  nearly  insoluble,  unless  the 
acid  be  in  excess. 

SUB-CARBONATE  OF  POTASS. 

41 

The  potass  of  commerce  is  always  in  the  state  of 
sub-carbonate ;  the  carbonic  acid  considerably  weakens 
its  alkaline  properties,  yet  it  will  still  change  vegetable 
colours  to  green,  and,  combined  with  oils,  will  form  an 
imperfect  soap. 

SUB-CARBONATE  OF  SODA. 

The  soda  of  commerce  is  in  the  state  of  sub-carbonate . 
but  its  carbonic  acid  deprives  it  of  more  of  its  alkaline 
properties  than  it  does  potass.  For  making  glass,  it  is 
used  in  the  state  of  a  sub-carbonate,  because  the  heat  is 
exposed  to  drive  off  the  carbonic  acid ;  but  to  form  soap, 
it  must  be  rendered  caustic,  which  is  effected  by  quick¬ 
lime. 


CARBONATE  OF  LIME. 

Carbonic  acid  has  the  power  of  completely  neutrali¬ 
zing  the  alkaline  properties  of  lime,  which  it  reduces  to 
a  state  in  which  it  is  nearly  tasteless.  Under  the  name 
of  chalk,  marble,  and  limestone,  we  shall  notice  this 
compound. 


FLUATES. 


The  fluates  are  not  decomposed  by  heat,  nor  altered 
by  combustibles :  when  sulphuric  acid  is  poured  upon 
them,  they  yield  acrid  vapours  of  fluoric  acid,  which 
corrodes  glass.  When  reduced  to  powder,  and  heated. 


19 


218  CHEMISTRY. 

but  not  made  red-hot,  some  of  them  become  phospho¬ 
rescent. 

The  principal  fluoric  salts  are  the  fluates  of  lime,  of 
soda,  of  potass,  of  ammonia,  of  barytes,  of  alumine,  of 
silex,  and  of  strontian ;  but  this  acid  forms  fluates  with 
mercury,  copper,  tin,  iron,  nickel,  and  several  othei 
metals,  The  whole  of  the  fluates  arc  factitious  salts 
except  those  of  lime  and  alumine. 

FLUATE  OF  LIME. 

Fluate  of  lime  is,  in  England,  well  known  under  fhe 
name  of  Derbyshire  spar,  or  Blue  John.  It  is  tasteless, 
and  nearly  insoluble  in  water.  It  is  not  altered  by  the 
air.  Its  specific  gravity  is  3.1.  When  powdered,  and 
heated  upon  a  shovel,  it  emits  a  violet-coloured  light ; 
but  this  ceases  if  it  be  made  red-hot.  It  is  fused  by  a 
strong  heat,  and  is  occasionally  used  as  a  flux.  It  exists 
in  the  enamel  of  the  human  teeth. 

FLUATE  OF  SILEX. 

The  fluoric  acid  gas  will  dissolve  silex,  and  still  re¬ 
tains  its  aerial  form  fbut  the  silex  is  afterwards  deposited 
in  crystals. 

B  O  R  A  T  E  S . 

The  Borates  are  all  fusible  into  glass,  and  assist  the 
fusion  of  other  bodies,  particularly  metals,  and  metallic 
oxides;  with  the  metallic  oxides,  they  form  glass  of  dif¬ 
ferent  colours. 

The  principal  salts  of  this  class,  are  the  sub-borate  of 
%oda,  the  borate  of  potass,  of  lime,  of  magnesia,  and  of 
alumine. 

SUB-BORATE  OF  SODA,  (BORAX.) 

This  is  the  oidy  borate  of  any  importance.  It  is  dug 
out  of  wells  in  the  kingdom  of  Thibet,  and  comes  to  us 
from  the  East  Indies.  It  is  then  in  a  state  of  impurity, 
and  is  called  tincal ;  when  purified,  it  receives  the  name 


ACETATES  OF  POTASS  AND  AMMONIA.  219 

of  borax.  It  is  in  whitish  crystals,  has  a  styptic  and 
alkaline  taste,  and  converts  vegetable  blues  to  green.  It 
is  soluble  in  twenty  times  its  weight  of  cold  water,  and 
six  times  its  weight  of  boiling  water.  When  melted  into 
glass,  it  is  transparent,  and  still  soluble  in  water.  When 
two  pieces  of  borax  are  struck  together  in  the  dark,  a 
flash  of  light  is  emitted.  Its  specific  gravity  is  1.740,  It 
slightly  effloresces  in  the  air. 

According  to  Bergman,  this  salt  consists  of  30  parts 
of  boracic  acid,  17  of  soda,  and  44  of  water.  It  is  much 
used  as  a  flux  in  soldering  metals  with  the  hard  solders. 

ACETATE  S. 

The  acetic  salts  are  distinguished  by  their  great  solu¬ 
bility  in  water ;  by  the  decomposition  of  the  acid  when 
the  solution  is  exposed  to  the  air;  by  their  being  decom¬ 
posed  by  heat,  and  by  their  yielding  acetic  acid  when 
mixed  with  sulphuric  acid,  and  distilled. 

The  principal  acetates  are  those  of  potass,  of  soda,  of 
ammonia,  of  magnesia,  of  barytes,  of  lead,  and  of  copper. 

ACETATE  OF  POTASS. 

This  salt  has  been  long  known,  and  has  been  distin¬ 
guished  by  almost  a  dozen  different  names  :  of  which  one 
was  secret  foliated  earth  of  tartar.  It  has  a  sharp 
warm  taste;  its  crystals  are  white,  and  in  the  form  of 
thin  plates.  It  is  soluble  in  alcohol,  in  ten  times  its 
weight  of  water,  and  is  deliquescent.  It  is  used  in  medi¬ 
cine.  It  was  formerly  made  from  distilled  or  even  com¬ 
mon  vinegar,  but  is  now  manufactured  from  pearl-ash 
and  purified  pyroligneous  acid. 

ACETATE  OF  AMMONIA. 

This  salt  tastes  like  a  mixture  of  sugar  and  nitre.  It 
is  extremely  volatile ;  and  cannot  be  crystallized,  except, 
by  an  extremely  slow  evaporation.  Its  crystals  are  long 
and  slender,  and  of  a  pearl-white  colour.  It  is  deliques¬ 
cent.  Its  solution  has  been  long  used  medicinally  under 
the  name  of  spirits  of  Mindererus. 


220 


CHEMISTRY. 


ACETATE  OF  LEAD,  (SUGAR  OF  LEAD.) 

This  salt  is  formed  by  the  solution  of  the  white  oxide 
of  lead  in  the  acetic  acid.  It  has  a  sweet  and  somewhat 
astringent  taste ;  and  is  sparingly  soluble  in  water.  It 
becomes  yellow  by  exposure  to  the  air.  Like  all  other 
preparations  of  lead,  it  is  a  strong  poison,  but  in  doses  of 
a  very  few  grains,  it  has  been  administered,  with  evident 
advantage,  in  desperate  -  cases  of  internal  hemorrhage. 
Its  solution  in  water  is  used  internally  as  ail  embrocation. 
That  decomposes  it.  It  is  used  considerably  by  the 
calico-printers  in  colour-making,  Alc. 

ACETATE  OF  COPPER. 

Acetate  of  copper  has  a  disagreeable,  coppery  taste; 
a  fine  deep  green  colour,  some  degree  of  unctuosity,  is 
efflorescent,  and  is  soluble  in  water  and  alcohol.  It  is 
used  in  dyeing:  a  small  quantity  of  it  does  very  well  in 
writing-ink.  It  is  also  used  in  painting.  In  chemistry, 
it  is  distilled  for  the  acetic  acid  it  affords. 

TV  RT  RATES. 

The  tartrates  are  decomposed  by  a  red  heat.  The 
earthy  tartrates  are  less  soluble  than  the  alkaline;  but 
they  are  all  capable  of  combining  with  another  base,  and 
forming  triple  salts. 

The  principal  tartrates  are  those  of  potass,  of  potass 
and  soda,  of  potass  and  ammonia,  of  lime,  of  strontian, 
and  of  potass  and  antimony. 

SUPER-TARTRATE  OF  POTASS 

Is  the  cream  of  tartar  of  the  stores.  It  has  a  strong, 
but  not  disagreeable  acid  taste*;  is  soluble  in  thirty  times 
its  weight  of  boiling  water;  and  is  not  altered  by  the  ex¬ 
posure  to  the  air.  According  to  Bergman,  it  contains  23 
parts  of  potass,  and  77  of  acid.  It  is  used  in  medicitie 
as  a  mild  aperient.  It  is  also  useful  in  dyeing. 


TARTRATES,  PHOSPHATES.  221 

TARTRATE  OF  POTASS  AND  SODA. 

This  triple  salt  is  sold  by  the  druggists  under  the 
name  of  Rochelle  salts.  It  has  a  strongly  saline  bitter 
taste ;  is  effervescent,  and  is  soluble  in  about  four  times 
its  weight  of  cold  water.  It  is  a  mild  cathartic 

TARTRATE  OF  POTASS  AND  ANTIMONY 

The  crystals  of  this  triple  salt  arc  of  a  white  colour, 
and  transparent.  It  is  soluble  in  60  parts  of  cold  water. 
It  is  formed  by  precipitating  the  muriate  of  antimony 
with  a  hot  solution  of  potass  in  distilled  water.  The 
precipitate  being  well  washed  and  dried,  nine  drachms 
are  to  be  boiled  in  five  pounds  of  water,  with  two  ounces 
and  a  half  of  super-tartrate  of  potass,  finely  powdered, 
till  the  powders  are  dissolved.  The  solution  must  then 
be  strained,  evaporated  to  a  pellicle,  and  left  to  crystallize. 
In  doses  of  from  two  to  four  grains,  this  is  the  best  and 
most  powerful  emetic  known. 

PHOSPHATES. 

The  phosphates  are  capable  of  vitrification;  are  par¬ 
tially  decomposed  by  sulphuric  acid;  are  phosphorescent 
at  a  high  temperature  ;  are  soluble  in  nitric  acid,  without 
effervescence  ;  and  may  be  precipitated  from  their  solu¬ 
tions  by  lime-vvater. 

The  principal  phosphates  are  those  of  potass,  of  soda, 
of  ammonia,  of  lime,  and  of  magnesia. 

PHOSPHATE  OF  SODA. 

The  phosphate  of  soda  has  nearly  the  same  taste  as 
common  salt ;  it  is  soluble  in  water,  and  efflorescent.  As 
a  cathartic,  it  is  equivalent  to  Glauber  and  Rochelle 
salts,  and  as  its  taste  is  much  pleasanter,  it  has  been  used 
instead  of  those  well-known  medicines.  It  may  be  ad¬ 
ministered  by  dissolving  in  a  weak  broth,  to  which  it 
11)  *  * 


CHEMISTRY. 


222 

serves  us  an  agreeable  seasoning.  Dr.  Pearson  first  pre¬ 
pared  and  introduced  it.  It  is  used  in  the  arts  as  a  flux 
instead  of  borax. 

PHOSPHATE  OF  SODA  AND  AMMONIA. 

This  compound,  which  was  formerly  called  nicrocomic 
salt,  is  much  used  as  a  flux  in  assays  with  the  blowpipe. 
It  may  be  obtained  from  human  urine  by  evaporation. 

PHOSPHATE  OF  LIME. 

Phosphate  of  lime  is  white,  tasteless,  and  insoluble  in 
water.  As  it  forms  the  bases  of  bones,  it  has  been  some 
times  called-  the  earth  of  hones.  It  exists  in  milk,  and 
some  other  animal  products,  also  in  wheat.  In  Spain  it 
has  been  found  abundantly  in  the  fossil  state. 

P  RUSSIA  TES. 

The  singular  affinities  of  some  prussiates  render  them 
interesting  to  the  chemist;  the  simple  prussiates  are, 
however,  little  regarded,  because  destitute  of  permanen¬ 
cy,  being  decomposed  merely  by  exposure  to  the  air, 
unless  united  with  a  metallic  oxide.  The  prussic  acid 
does  not  appear  capable  of  saturating  an  alkali ;  and 
the  weakest  acid  known  is  capable  of  decomposing  the 
prussiates  of  the  earths  and  the  alkalies. 

The  most  important  of  the  simple  prussiates  is  that  of 
iron ;  and  of  triple  prussiates,  those  of  potass,  soda,  lime, 
and  ammonia  with  iron. 

PRUSSIATE  OF  IRON. 

The  prussiate  of  iron,  or  prussian  blue,  is,  according 
to  Proust,  a  combination  of  the  prussic  acid  and  red 
oxide  of  iron.  With  the  green  oxide,  the  prussic  acid 
forms  a  white  compound,  which,  however,  becomes 
gradually  blue  by  exposure  to  the  atmosphere,  from  the 
absorption  of  oxygen.  It  is  a  fine  deep  blue,  and  valua¬ 
ble  as  a  pigment ;  it  is  insoluble  in  water,  very  sparingly 


223 


PHUSSlATESj  OXIDES. 

soluble  in  acids,  and  not  affected  l>v  exposure  to  the  air 
It  is  composed  of  equal  parts  of  the  acid  and  the  oxide. 
If  exposed  to  a  strong  heat,  the  acid  is  destroyed,  and 
the  residuum  is  simply  oxide  of  iron.  If  the  blue  prus- 
siate  of  iron  be  deprived  of  part  of  its  acid,  by  digesting 
it  with  alkalies,  it  becomes  yellowish. 

PRUSSIATE  OF  POTASS  AND  IRON. 

This  compound  is  often  called  prussian  alkali,  or  prus- 
sian  test.  The  importance  of  it  to  chemists,  consists  in 
its  being  capable  of  indicating  whether  a  metal  be  pre¬ 
sent  in  any  solution  whatever,  unless  the  metal  be  pla- 
tina ;  and  the  colour  of  the  precipitate  differing  with  the 
metal,  even  the  name  of  the  metal  may  be  known.  It 
is  necessary  to  take  great  care  to  have  it  perfectly  pre¬ 
pared,  otherwise  it  will  afford  false  results.  We  have 
given  Henry’s  directions  respecting  its  preparations  under 
the  head  of  prussic  acid.  Its  crystals  should  be  well  pre¬ 
served  in  a  well  stopped  bottle  tilled  with  alcohol  in 
which  they  are  insoluble. 

OF  OXIDES. 

Whex  the  oxygen  united  to  any  of  the  simple  sub¬ 
stances  does  not  give  it  the  properties  of  an  acid  or  an 
alkali,  the  compound  is  called  an  oxide. 

Most  of  the  metals  are  capable  of  combining  with  dif¬ 
ferent  proportions  of  oxygen,  and  a  difference  in  the  pro¬ 
portion  of  oxygen  gives  a  different  colour  to  the  oxide. 

Some  oxides  require  only  an  additional  quantity  of 
oxygen  to  convert  them  into  acids;  others  always  retain 
the  character  of  oxides,  whether  possessed  of  the  highest 
or  the  lowest  quantity  with  which  they  will  combine. 

Oxides  cannot  be  formed  except  oxygen  be  present, 
and  the  oxide  of  any  substance  is  heavier  than  the  sub¬ 
stance  itself,  by  a  quantity  exactly  equal  to  the  oxygen 
received.  The  young  student  may  be  reminded,  that  by 
the  term  heavier,  it  is  not  meant  that  the  density  or 


CHEMISTRY. 


224 

specific  gravity  of  the  oxide  is  greater  than  its  base,  but 
the  total  quantity  of  it  weighs  more. 

Oxides  are  in  general  friable  or  pulverulent,  and  have 
the  appearance  of  earths ;  but  one  of  them  is  a  fluid, 
and  some  of  them  are  gases. 

OXIDES  OF  NITROGEN. 

Nitrogen  combines  in  two  proportions  with  oxygen, 
without  producing  an  acid.  It  therefore  furnishes  two 
oxides,  which  are  distinguished  from  each  other,  like  the 
acids,  by  a  difference  in  the  termination  of  the  word 
denoting  the  base ;  they  are  the  nitrous  oxide  and  nitric 
oxide. 

jYitrous  oxide. — This  gas,  which  is  also  known  by  the 
name  of  gaseous  oxide  of  nitrogen ,  is  composed  of  G3 
parts  of  nitrogen,  and  37  of  oxygen  by  weight.  It  has 
a  faint  smell,  and  imparts  a  slight  sensation  of  sweetness, 
when  respired.  It  is  dissolved  by  water ;  but  may  be 
expelled  from  the  water  by  heat  unchanged.  Alcohol 
absorbs  more  of  it  than  water,  and  the  essential  and 
fixed  oils  more  than  alcohol;  but  heat  expels  it  from  all 
these  combinations.  It  supports  combustion  with  more 
activity  than  common  air  ;  but  it  is,  in  general,  necessary 
that  the  combustible  should  be  kindled  in  the  atmosphere 
or  oxygen.  It  may  be  respired  for  a  few  minutes ;  and 
the  extraordinary  effects  it  produces  on  the  system,  du¬ 
ring  its  respiration,  and  for  a  short  time  after,  occasions 
it  to  be  frequently  made  for  this  purpose,  which  is  the 
only  use,  (if  it  may  be  called  use,)  to  which  it  may  be 
applied.  To  inhale  it  superinduces  a  species  of  intoxica¬ 
tion  ;  the  mind  of  the  person  is  last  for  a  moment  to  a 
right  consciousness  of  things  around  him.  In  general,  he 
laughs  involuntarily  and  extravagantly ;  exhibits  the 
most  frantic  or  preposterous  gesticulations,  and  violent 
muscular  exertion,  and  feels,  at  the  same  time,  delight¬ 
fully  happy.  In  a  few  moments,  after  having  ceased  to 
breathe  the  gas,  its  eil'ects  go  off  With  nearly  all  per 
sons  who  have  breathed  this  gas,  not  the  least  uneasi¬ 
ness  or  languor  subsequently  remains ;  it  has  even  re 


OXIDES  OF  NITROGEN.  225 

Covered  some  from  a  state  of  Casual  debility,  and  restored 
them  to  comfortable  enjoyment;  but,  as  there  are  others 
on  whom  less  favourable  effects  have  been  produced,  it 
may  be  a  useful  caution  for  those  who  have  nevei 
breathed  it,  or  who  are  not  in  perfect  health,  to  take, 
in  the  first  instance,  but  a  small  dose. 

As  it  is  important  that  the  nitrous  oxide  intended  to 
be  inhaled  should  be  perfectly  pure,  it  may  be  proper  to 
observe,  that  it  can  only  be  prepared  with  certainty  by 
the  decomposition  of  nitrate  of  ammonia.  For  this  pur¬ 
pose,  nitric  acid,  diluted  with  five  or  six  parts  of  water, 
may  be  saturated  with  carbonate  of  ammonia,  and  the 
solution  evaporated  by  a  gentle  heat,  adding,  occasion¬ 
ally,  a  little  of  the  carbonate,  to  supply  what  is  carried 
off!  The  nitrate  crystallizes  in  a  fibrous  mass,  unless  the 
evaporation  has  been  carried  so  far  as  to  leave  it  dry 
and  compact. 

The  nitrate  should  be  put  into  a  retort,  and  a  lamp 
furnace  should  be  employed  to  decompose  it ;  as  the  heat 
employed  should  not  be  raised  above  450°.  A  pound 
of  the  nitrate  of  ammonia  will  yield  about  5  cubical 
feet  of  the  gas,  which  should  be  received  over  water, 
and  afterwards  allowed  to  stand  an  hour  or  two  in  con¬ 
tact  with  the  water,  which  will  absorb  any  ammonia 
that  may  have  been  sublimed,  or  any  acid  that  may 
happen  to  be  present. 

JVitric  oxide,  (sometimes  called  nitrous  gas.)  Thit 
gas  is  composed  of  44  parts  of  nitrogen,  and  5(3  of  oxyger 
by  weight.  It  is  an  invisible  gas,  until  it  comes  in  con¬ 
tact  with  the  atmosphere,  or  some  air  which  contains 
oxygen,  when  it  assumes  an  orange  colour.  It  is  interest¬ 
ing  to  observe  the  difference  between  this  gas,  and  the 
preceding,  from  which  it  only  differs  in  containing  a  few 
parts  more  oxygen  ;  this  gas  instantly  kills  the  animals 
which  breathe  it;  and  even  destroys  plants.  In  general, 
also,  it  extinguishes  light,  but  some  substances  have  the 
property  of  decomposing  it,  if  inflamed  before  being  put 
into  it,  and  of  then  burning  with  considerable  splendour. 

Dr.  Priestley  foupd  that  water  was  capable  of  absorb* 

P 


226 


CHEMISTRY. 


ing  about  one  tenth  of  nitric  oxide,  from  which  it  ac¬ 
quired  an  astringent  taste ;  and  that  the  water  gave  out 
the  whole  of  this  gas  when  passing  to  the  state  of  ice. 
Oils  greedily  absorb  nitric  oxide,  and  decompose  it. 
Nitric  acid  also  absorbs  it,  and  is  converted  by  the 
absorption  into  nitrous  acid,  becoming  fuming  and  col¬ 
oured  at  the  same  time. 

Nitric  acid  is  composed  of  75  parts  of  oxygen  and  25 
parts  of  nitrogen ;  it,  therefore,  bears  a  very  near  rela¬ 
tion  to  this  gas,  which  may  be  converted  into  it,  by  sim¬ 
ply  mixing  it  with  a  due  proportion  of  oxygen. 

OXIDE  OF  HYDROGEN. 

Hydrogen  appears  to  be  capable  of  combining  with 
<>xygen  only  in  one  proportion,  and  that  one  forms  water, 
which  is  the  oxide  of  hydrogen. 

CARBONIC  OXIDE. 

Carbon,  combined  with  60  per  cent,  of  oxygen,  forms 
carbonic  oxide,  which  is  an  invisible  and  elastic  gas,  of 
rather  less  specific  gravity  than  common  air.  This  gas 
is  not  fit  for  respiration,  nor  will  it  support  combustion; 
but  it  will  itself  burn,  with  a  lambent  blue  flame,  in 
atmospheric  air.  This  is  the  only  oxide  of  carbon  which 
has  been  obtained. 

OXIDE  OF  SULPHUR. 

Sulphur,  if  kept  for  some  time  in  fusion  in  an  open 
vessel,  absorbs  about  2.4  per  cent,  of  oxygen.  This  is 
the  only  oxide  of  it  which  is  known  ;  it  is  of  a  red  colour, 
and  is  used  for  taking  impressions  of  metals. 

OXIDE  OF  PHOSPHORUS. 

The  brown  colour  which  phosphorus  acquires  by  ex¬ 
posure  to  the  air,  is  in  consequence  of  its  combination 
with  oxygen,  and  this  brown  part  is  the  oxide  of  phos¬ 
phorus.  Phosphorus  when  mixed  with  its  oxide,  which 
it  generally  is  when  newly  prepared,  may  be  purified  by 
putting  it  into  hot  water  ;  the  oxide  swims  on  the  surface. 


METALLIC  OXIDES. 


227 


METALLIC  OXIDES. 

Metallic  oxides  are  exceedingly  numerous ;  every 
metal  is  capable  of  forming  at  least  one  oxide,  and  most 
metals  are  capable  of  forming  several  by  combining  with 
different  proportions  of  oxygen.  The  oxygen  which  en¬ 
ters  into  their  composition,  has  the  singular  effect  of 
depriving  them  entirely  of  their  lustre  and  cohesion,  and 
reducing  them  to  the  state  of  earths. 

An  acid  has  no  action  upon  a  metal,  unless  the  oxygen 
it  contains  has  a  greater  attraction  for  the  metal  put  into 
it,  than  for  the  base  of  the  acid.  The  acids  first  impart 
oxygen  to  metals,  and  then  dissolve  the  oxide. 

The  metals,  in  the  readiness  with  which  they  imbibe 
oxygen,  and  the  firmness  with  which  they  retain  it,  differ 
very  considerably.  From  some,  as  manganese,  it  cannot 
be  separated  without  difficulty ;  from  others,  as  gold, 
silver,  and  platina,  it  is  ever  ready  to  separate,  because 
of  their  slight  affinity  for  it,  which  constitutes  their  dis¬ 
position  to  resume  their  metallic  state,  and  is  the  leading 
property  of  what  are  called  noble  metals. 

From  the  beauty  and  fixedness  of  the  colours  of  many 
of  the  metallic  oxides,  they  are  used  as  pigments  in 
painting  in  oil  and  water  colours ;  and  as  they  are  con¬ 
vertible  into  glass,  they  are  admirably  adapted  for  painting 
on  enamel  and  porcelain.  A  purple  colour  is  given  by 
gold;  yellow  by  silver:  green  by  copper;  red  by  iron; 
blue  by  cobalt ;  and  violet  by  manganese. 

As  carbon  and  hydrogen  have  a  stronger  attraction  for 
oxygen  than  other  substances,  they,  or  the  substances 
consisting  chiefly  of  them,  are  employed  for  reducing 
metallic  oxides;  the  metallic  oxide  is  mixed  up  with 
charcoal,  oil,  fat,  resin,  or  the  cheapest  inflammable  body 
which  can  be  obtained,  and  submitted  in  a  crucible  to  a 
strong  heat;  the  oxygen  of  the  oxide  combines  with  the 
hydrogen  or  carbon  which  is  present,  and  the  metal 
is  obtained  in  its  metallic  state  at  the  bottom  of  the 
crucible. 


228 


CHEMISTRY. 


ORGANIC  SUBSTANCES 

VEGETABLES. 

Vegetables,  though  infinitely  diversified  in  their  ap¬ 
pearance  and  properties,  are  found  to  consist  of  a  smal. 
number  of  simple  substances  ;  carbon  is  the  basis  of  them 
all,  and  after  carbon,  hydrogen  and  oxygen  may  be.  con¬ 
sidered  as  forming  the  principal  part  of  them.  Some 
vegetables  contain  nitrogen,  others  phosphorus,  earths, 
and  metals,  but  these  elements  are  not  general ;  they 
belong  only  to  particular  plants,  or  to  plants  in  particulai 
situations. 

Although  the  proportions  of  the  component  parts  of 
vegetables  may  be  ascertained  with  considerable  accu 
racy,  yet  the  chemist  is  unable  to  combine  these  com 
ponent  parts  in  any  manner  that  shall  produce  substan 
ces  resembling  the  entire  vegetable,  or  the  compounded 
products  which  it  affords. 

Plants  derive  a  principal  part  of  their  nourishment 
from  water ;  their  roots  imbibe  the  water,  which  is 
decomposed  in  them,  by  the  assistance  of  light  and  heat; 
and  a  part  of  its  hydrogen  becomes  fixed,  while  a  part, 
at  least,  of  the  oxygen  is  given  out  hy  transpiration. 
Water  will  hold  carbon,  in  solution,  deriving  it  from  the 
soil;  and  hence  the  utility  of  dung,  or  putrefying  animal 
or  vegetable  substances,  which  supply  a  large  quantity 
of  carbon,  as  well  as  hydrogen  and  nitrogen.  Plants 
will  grow,  although  their  roots  stand  in  such  materials 
as  lose  no  portion  of  their  weight,  and  although  they  be 
watered  with  distilled  water.  In  this  case,  the  carbon 
of  the  plants  is  derived  from  the  atmosphere,  through  the 
medium  of  the  leaves.  Perhaps,  at  all  times,  the  atmo¬ 
sphere  furnishes  a  part  of  the  carbon,  through  the 
medium  of  the  under-surface  of  the  leaves;  but  when 
an  adequate  supply  is  derived  from  the  roots,  the  leaves 
perform  this  office  with  less  energy.  Water  impreg- 


ORGANIC  SUBSTANCES. 


229 


nated  with  carbonic  acid  gas,  renders  vegetation  more 
vigorous. 

The  processes  of  vegetation  have  a  considerable  ten¬ 
dency  to  produce  equality  of  temperature.  If  the  bulb 
of  a  thermometer  be  plunged  into  a  hole  in  a  tree,  it 
indicates  a  higher  temperature  than  the  atmosphere  in 
cold  weather,  and  a  lower  temperature  in  hot  weather. 

The  most  usual  compound  substances,  furnished  by 
vegetables,  and  which  are  possessed  of  remarkable  or 
distinct  characters,  we  shall  consider  separately. 

SUGAR. 

Sugar  is  afforded  by  most  plants,  and  in  some,  such 
as  the  sugar-cane,  the  beet-root,  the  sugar-maple,  the 
carrot,  it  is  particularly  abundant.  It  crystallizes,  is 
sweet  to  the  taste,  and  soluble  in  water  and  alcohol. 
Used  as  food,  it  is  extremely  nourishing  and  antiseptic, 
Treated  with  nitric  acid,  it  affords  oxalic  acid.  Lime 
barytes,  magnesia,  and  strontian,  are  soluble  in  the  solu¬ 
tion  of  sugar.  One  hundred  parts  of  sugar,  contain  of 
carbon  28  parts,  of  hydrogen  8,  and  of  oxygen  G4. 

STARCH,  OR  FECULA. 

Starch  is  white,  insipid,  insoluble  in  cold  water  or 
alcohol.,  but  forming  with  boiling  water  a  semi-transpa¬ 
rent  jelly.  It  is  abundant  in  potatoes,  wheat,  barley, 
and  many  other  plants,  roots,  and  seeds,  and  may  be 
separated  from  them  by  maceration  in  water.  It  dis¬ 
solves  in  cold  water  that  contains  an  acid  or  an  alkali. 

Fecula  is  often- used  as  a  general  term  for  all  matters 
contained  in  the  juices  of  plants,  and  not  held  in  solution 
by  them ;  sometimes  we  hear  of  amylaceous  fecula 
this  is  the  same  with  starch ;  green  fecula  is  also  an 
expression  in  use,  but  the  green  colour  of  fecula  is  sel¬ 
dom  permanent.  Indigo  is  a  blue  fecula. 

20 


230 


CHEMISTRY. 


ALBUMEN. 

Albumen  is  most  abundant  in  those  vegetables  which 
ferment  and  afford  a  vinous  liquor  without  yeast.  It  is 
soluble  in  cold  water ;  but  its  chief  characteristic  is,  that 
it  coagulates  and  becomes  insoluble  by  heat. 

GLUTEN. 

If  wheaten  flour  be  kneaded  in  cold  running  water, 
the  water  will  carry  off  the  mucilage  and  starch  it  con¬ 
tains  ;  and,  when  the  water  runs  off  colourless,  a  pecu¬ 
liar  substance  will  remain,  which  is  called  gluten. 

Gluten  composes  about  one-twelfth  of  the  matter  of 
wrheaten  flour ;  it  is  ductile  and  elastic,  and  of  a  stringy 
texture:  it  has  some  smell,  but  no  taste.  If  stretched 
out,  it  returns  to  its  original  state.  By  exposure  to  the 
air,  it  becomes  brown,  and  appears  to  have  an  oily  coat¬ 
ing.  When  completely  dry,  it  is  very  brittle,  and  resem¬ 
bles  glue.  If  kept  moist,  it  soon  putrefies.  It  is  insoluble 
in  water,  alcohol,  or  ether ;  but  the  acids  dissolve  it,  and 
the  alkalies  precipitate  it.  No  other  vegetable  product 
has  so  near  an  alliance  to  animal  matter,  both  in  its 
appearance,  which  is  like  that  of  tendons,  and  in  its 
constituent  parts,  into  which  nitrogen  largely  enters,  and 
some  ammonia. 

GELATINE. 

Gelatine,  or  jelly,  has  some  resemblance  to  albumen, 
but  differs  from  it  in  not  being  coagulated  by  heat.  It 
is  soluble  in  water,  insipid,  and  precipitated  by  infusion 
of  galls.  It  may  be  procured  from  blackberries,  and 
other  fruits  of  a  similar  kind. 

BITTER  PRINCIPLE. 

The  bitter  principle  of  vegetables  is  soluble  in  water 
and  alcohol.  It  is  soluble  in  nitric  acid,  and  precipitated 
by  nitrate  of  silver.  Its  colour  is  yellow,  or  brown.  Hops, 
quassia,  &c.  contain  much  of  it. 


ORGANIC  SUBSTANCES. 


231 


,  NARCOTIC  PRINCIPLE. 

The  narcotic  principle  is  soluble  in  400  parts  of  hot 
water ;  alcohol  dissolves  a  twenty-fourth  part  of  it.  It 
is  crystallizable,  and  of  a  white  colour.  It  is  soluble  in 
all  the  acids  without  heat,  and  is  precipitated  from  them 
in  a  white  powder  by  alkalies. 

EXTRACTIVE  MATTER. 

Extractive  matter  is  taken  up  from  vegetables  by 
water  and  alcohol ;  and,  therefore,  is  soluble  in  these 
fluids.  It  is  insoluble  in  ether.  It  is  precipitated  by 
oxymuriatic  acid,  muriate  of  tin,  and  muriate  of  alumine, 
but  not  by  gelatine.  It  dyes  a  fawn  colour.  In  the 
roots  of  liquorice,  it  is  abundant. 

TANNIN. 

Tannin  is  the  name  given  to  the  peculiar  principle 
which  combines  with  the  gelatine  of  skins,  and  converts 
them  into  leather.  It  is  found  in  the  gall-nut,  and  in 
all  vegetables,  or  parts  of  vegetables,  which  are  called 
astringent.  It  has  by  some  been  deemed  the  astringent 
principle.  It  is  soluble  in  water  and  alcohol,  but  is  pre¬ 
cipitated  by  gelatine,  with  which  it  forms  an  insoluble 
compound,  that  becomes  solid  and  elastic. 

WAX. 

Wax  is  in  its  composition  very  analogous  to  fixed 
oil.  It  is  a  vegetable  product:  bees  are  merely  the 
labourers  by  whom  it  is  collected;  they  do  not  alter  its 
nature.  If  the  nitric  or  muriatic  acid  be  digested  for 
several  months  upon  a  fixed  oil,  the  oil  passes" to  a  sub¬ 
stance  resembling  wax.  Hence  wax  might  be  inferred 
to  be  a  fixed  oil  concreted  by  the  absorption  of  oxygen. 
Its  natural  colour  is  yellow,  but  it  may  be  whitened  by 
exposing  it  in  thin  laminae  to  the  air  and  sun.  Alkalies 
dissolve  wax,  and  render  it  miscible  with  water. 

In  China  and  in  North  America,  wax  is  obtained  di¬ 
rectly  from  plants,  and  is  then  called  vegetable-wax. 


232 


CHEMISTRY. 


HONEY. 

Honey,  like  wax,  is  gathered  by  bees,  ready  formed 
from  flowers,  which  contain  it  in  an  organ  called  a  nec¬ 
tary  ;  it  is  deleterious  when  gathered  in  districts  where 
poisonous  shrubs  abound,  of  which  there  are  many  ex¬ 
amples  in  the  uncultivated  parts  of  America.  Honey  is 
composed  of  sugar,  mucilage,  and  water. 

BIRD-LIME. 

Bird-lime  is  of  a  greenish  colour,  has  the  smell  of 
linseed  oil,  is  insipid  to  the  taste,  and  is  extremely  viscid. 
It  is  perfectly  soluble  in  ether,  sparingly  so  in  alcohol, 
and  insoluble  in  water.  By  exposure  to  the  air,  it  be¬ 
comes  dry  enough  to  be  powdered,  but  recovers  its 
viscidity  by  wetting  it.  It  reddens  tincture  of  litmus. 

The  best  bird-lime  is  supplied  by  the  middle  bark  of - 
the  holly,  which  is  boiled  in  water,  left  to  ferment  for 
several  weeks,  and  afterwards  macerated  in  water. 

COLOURING  MATTER. 

The  colouring  matter  of  vegetables  is  combined  with, 
1,  the  extractive  principle  ;  2,  with  resin  ;  3,  with  fecula; 
4,  with  gum.  Most  of  the  colouring  matters  of  vegeta¬ 
bles  have  a  great  affinity  for  the  earths,  particularly  for 
alumine  ;  and  for  the  white  metallic  oxides,  especially 
the  white  oxide  of  tin;  also  for  animal  fibrous  matters, 
and  for  oxygen.  On  a  due  regard  to  these  affinities, 
depends  the  art  of  dyeing. 

Berthollet  remarks,  that  those  colouring  matters  which 
contain  the  most  Carbon,  allbrd  the  richest  and  most 
’asting  colours.  Indigo  is  of  this  class. 

WOODY  FIBRE. 

When  thin  shavings  of  wood  are  boiled  in  water,  to 
separate  the  extractive  matter,  and  afterwards  in  alcohol, 
to  dissolve  the  resin,  a  residuum-  is  obtained  called  the 
icoody  fibre.  It  constitutes  the  basis  of  the  solid  part  of 
vegetables.  It  is  tasteless,  insoluble  in  water  or  alcohol. 


ORGANIC  SUBSTANCES. 


233 


but  it  is  soluble  in  weak  alkaline  solutions,  and  is  precip¬ 
itated  by  acids.  It  is  also  soluble  in  nitric  acid,  and 
yields  oxalic  acid.  It  is  not  liable  to  putrefaction  by 
exposure  to  the  air.  It  consists  principally  of  carbon, 
and  therefore,  when  burnt  in  close  vessels,  affords  much 
charcoal. 

BALSAMS. 

Balsax\is  have  a  strong  and  fragrant  smell :  most  of 
them  are  semi-fluids.  When  heated,  the  benzoic  acid 
sublimes  from  them,  which  constitutes  the  principal  dis¬ 
tinction  between  them  and  resins.  Like  resins,  they  are 
obtained  by  incisions  made  in  the  trees  affording  them. 

RESINS. 

Resins  are  mostly  insoluble  in  water,  but  when  pure, 
they  are  soluble  in  alcohol,  oils,  ether,  alkalies,  and  acetic 
acid.  They  are  sometimes  brittle,  sometimes  soft  and 
tough,  and  they  all  become  fluid  by  heat.  The  nitric 
acid  converts  them  into  tannin.  By  distillation,  they 
afford  volatile  oil.  They  are  all  electric,  and  their 
electricity  is  negative.  During  combustion  they  afford 
much  smoke. 

MUCILAGE,  OR  GUM. 

The  mucilage  of  vegetables  is  usually  transparent, 
more  or  less  brittle  when  dry,  though  difficultly  pulvera- 
ble  ,’  of  an  insipid,  or  slightly  saccharine  taste;  soluble 
in,  or  capable  of  combining  with  water  in  all  proportions, 
to  which  it  gives  a  gluey  adhesive  consistence,  in  propor¬ 
tion  as  its  quantity  is  greater.  It  is  separable,  or  coagu¬ 
lates  by  action  of  weak  acids ;  it  is  insoluble  in  alcohol, 
and  in  oil ;  and  capable  of  the  acid  fermentation,  when 
diluted  with  water.  The  destructive  action  of  fire 
causes  it  to  emit  much  carbonic  acid,  and  converts  it 
into  coal,  without  exhibiting  any  flame.  Distillation 
affords  water,  acid,  a  small  quantity  of  oil,  a  small  quan¬ 
tity  of  ammonia,  and  much  coal. 

These  are  the  leading  properties  of  gums,  rightly  so 
20  * 


CHEMISTRY. 


234 

called ;  but  the  inaccurate  custom  of  former  times  ap 
plied  the  term  gum  to  all  concrete  vegetable  juices;  so 
that  in  common  we  hear  of  gum  copal,  gum  sandarach, 
nd  other  gums,  which  are  either  pure  resins,  or  mixture 
of  resins  with  vegetable  mucilage. 

The  principal  gums  are,  1.  the  common  gums,  ob¬ 
tained  from  the  plum,  the  peach,  the  cherry-tree,  &c. 
2.  Gum-arabic,  which  flows  naturally  from  the  acacia,  in 
Egypt,  Arabia,  and  elsewhere.  This  forms  a  clear 
transparent  mucilage  with  water.  3.  Gum-seneca  or 
Senegal.  It  does  not  greatly  differ  from  gum-arabic ; 
the  pieces  are  larger  and  clearer,  and  it  seems  to  com¬ 
municate  a  higher  degree  of  the  adhesive  quality  to 
water.  It  is  much  used  by  calico-printers,  and  others. 
The  first  sort  of  gums  are  frequently  sold  by  this  name, 
but  may  be  known  by  their  darker  colour.  4.  Gum 
adragant  or  tragacanth.  It  is  obtained  from  a  small 
plant,  a  species  of  astragalus,  growing  in  Syria,  and 
other  eastern  parts.  It  comes  to  us  in  small,  white, 
contorted  pieces,  resembling  worms.  It  is  usually  dearer 
than  other  gums,  and  forms  a  thicker  jelly  with  water. 

GUM  ARABIC. 

The  Egyptian  thorn  yields  the  true  acacia  gum ,  or 
gum-arabic.  Cairo  and  Alexandria  were  the  principal 
marts  for  gum-arabic,  till  the  Dutch  introduced  the  gum 
from  Senegal  into  Europe,  about  the  beginning  of  the 
seventeenth  century  ;  and  this  source  now  supplies  the 
greater  part  of  the  vast  consumption  of  this  article.  The 
tree  which  yields  the  Senegal  gum  grows  abundantly  on 
the  sands  along  the  whole  of  the  Barbary  coast,  and  par¬ 
ticularly  about  the  river  Senegal.  There  are  several 
species,  some  of  which  yield  a  red  astringent  juice;  but 
others  aflord  only  a  pure,  nearly  colourless,  insipid  gum, 
which  is  the  great  article  of  commerce.  These  trees 
sre  from  eighteen  to  twenty  feet  high,  with  thorny 
branches.  The  gum  makes  its  appearance  about  the 
middle  of  November,  when  the  soil  has  been  thoroughly 
saturated  with  periodical  rains.  The  gummy  juice  is 


ORGANIC  SUBSTANCES. 


235 


seen  to  ooze  through  the  trunk  and  branches,  and,  in 
about  a  fortnight,  it  hardens  into  roundish  drops,  of  a 
yellowish-white,  which  are  beautifully  brilliant  where 
they  are  broken  off,  and  entirely  so,  when  held  in  the 
mouth  for  a  short  time,  to  dissolve  the  outer  surface.  No 
clefts  are  made,  nor  any  artificial  means  used  by  the 
Moors,  to  solicit  the  flowing  of  the  gum.  The  lumps  of 
gum-senegal  are  about  the  size  of  partridge-eggs,  and 
the  harvest  continues  about  six  weeks.  This  gum  is  a 
very  wholesome  and  nutritious  food ;  thousands  of  the 
Moors  supporting  themselves  entirely  upon  it  during  the 
time  of  harvest.  About  six  ounces  is  sulficient  to  support 
a  man  a  day ;  and  it  is  besides  mixed  with  milk,  animal 
broths,  and  other  victuals. 

Gum-arabic,  or  that  which  comes  directly  from  Egypt 
and  the  Levant,  only  differs  from  the  gum-senegal,  in 
being  of  a  lighter  colour,  and  in  smaller  lumps;  and  it 
:s,  also,  somewhat  more  brittle.  In  other  respects,  they 
resemble  each  other  perfectly. 

GUM  SENEGAL. 

See  Gum-arabic. 

GUM  TRAGACANTII. 

We  are  indebted  to  a  French  traveller,  by  the  name 
of  Oliver,  for  the  discovery,  that  the  gum-tragacanth  of 
commerce,  is  the  produce  of  a  species  of  astragalus,  not 
before  known.  He  describes  it,  under  the  name  of  as¬ 
tragalus  verus.  It  grows  in  the  north  of  Persia.  Gum- 
tragacanth,  or  gum-dragon,  (which  is  forced  from  this 
plant  by  the  intensity  of  solar  rays,  is  converted  into 
irregular  lumps,  or  vermicular  pieces,  bent  into  a  variety 
of  shapes,  and  larger  or  smaller  proportions,  according  to 
the  size  of  the  wood  from  which  it  issues,)  is  brought 
chiefly  from  Turkey.  The  best  sort  is  white,  semi¬ 
transparent,  dry,  yet  somewhat  soft  to  the  touch. 

Gum-tragacanth  differs  from  all  other  gums,  in  giving 
a  thick  consistency  to  a  much  larger  quantity  of  water, 
and  in  being  much  more  difficultly  soluble,  or  rather 


236 


CHEMISTRY. 


dissolves  only  imperfectly.  Put  into  water,  it  slowly  im 
bibes  a  great  quantity  of  the  liquid,  swells  into  a  large 
volume,  and  forms  a  soft,  but  not  fluid  mucilage:  if  more 
water  be  added,  a  fluid  solution  may  be  obtained  by 
agitation  ;  but  the  liquor  looks  turbid  and  whitish,  and 
on  standing,  the  mucilage  subsides,  the  limpid  water 
on  the  surface  retaining  little  of  the  gum.  Nor  does  the 
admixture  of  the  preceding  more  soluble  gums  promote 
its  union  with  the  water,  or  render  it  dissoluble,  or  more 
durable.  When  gum-tragacanth  and  gum-arabic  are 
dissolved  together  in  water,  the  tragacanth  separates 
from  the  mixture  more  speedily  than  when  dissolved  by 
itself. 

Tragacanth  is  usually  preferred  to  other  gums  for 
making  up  torches,  and  other  like  purposes,  and  is  sup¬ 
posed  likewise  to  be  the  most  effectual  as  a  medicine. 

According  to  Bucholtz,  gum-tragacanth  is  composed 
of  57  parts  of  a  matter  similar  to  gum-arabic,  and  43  of 
a  peculiar  substance,  capable  of  swelling  in  cold  water 
without  dissolving,  and  assuming  the  appearance  of  a 
thick  jelly.  It  is  soluble  in  boiling  water,  and  then  forms 
a  mucilaginous  solution. 

BRITISH  GUM. 

When  starch  is  exposed  to  a  temperature  between 
600°  and  700°  it  swells,  and  exhales  a  peculiar  smell;  it 
becomes  of  a  brown  colour,  and  in  that  state  is ‘employed 
by  calico-printers.  It  is  soluble  in  cold  water,  and  does 
not  form  a  blue  compound  with  iodine.  Vanquelin  found 
it  to  differ  from  gum  in  affording  oxalic  instead  of  mucous 
acid,  when  treated  with  nitric  acid. 

GUM  COPAL. 

(The  American  name  of  all  clear  odoriferous  gums.) 
This  resinous  substance  is  imported  from  Guiana,  where 
it  is  found  in  the  sand  on  the  shore.  It  is  a  hard,  shining, 
transparent,  citron  coloured,  odoriferous,  concrete  juice 
of  an  American  tree,  but  which  has  neither  the  solubility 
in  water  common  to  gums,  nor  the  solubility  in  alcohol 


ORGANIC  SUBSTANCES. 


237 


common  to  resins,  at  least  in  any  considerable  degree. 
By  these  properties  it  resembles  amber.  It  may  be  dis¬ 
solved  by  digestion  in  linseed  oil,  rendered  drying  by 
quick-lime,  with  a  heat  very  little  less  than  sufficient  to 
boil  or  decompose  the  oil.  This  solution,  diluted  with 
oil  of  turpentine,  forms  a  beautiful  transparent  varnish, 
which,  when  properly  applied,  and  slowly  dried,  is  very 
hard  and  durable.  This  varnish  is  applied  to  snutF 
boxes,  tea-boards,  and  other  utensils.  It  preserves  and 
gives  lustre  to  paintings,  and  greatly  restores  the  decayed 
colours  of  old  pictures,  by  filling  up  the  cracks,  and  ren¬ 
dering  the  surfaces  capable  of  reflecting  light  more 
uniformly. 

CAOUTCHOUC  OR  GUM-ELASTIC. 

Gum-elastic  or  Indian  rubber,  possesses  great  elas¬ 
ticity;  is  soluble  in  water  and  alcohol,  is  reduced  to  a 
pulp  by  heated  spirits  of  turpentine,  but  is  strictly  soluble 
only  in  nitric  ether  and  naphtha.  The  solution  is  ex¬ 
tremely  adhesive,  and  slow  in  drying. 

Caoutchouc  always  remains  soft,  like  leather,  unless 
in  a  very  low  temperature ;  it  is  fusible,  and  burns  like 
resins,  but  with  less  smoke. 

Caoutchouc  is  prepared  chiefly  from  the  juice  of  the 
Siphanica  elastica.  The  manner  of  obtaining  this  juice 
is  by  making  incisions  through  the  bark  of  the  trunk  of 
the  lower  part  of  the  tree,  from  which  the  fluid  resin 
issues  in  great  abundance,  appearing  of  a  milky  white¬ 
ness  as  it  flows  into  the  vessel  placed  to  receive  it,  after 
which  it  inspissates  into  a  soft,  reddish,  elastic  resin.  It 
is  now  manufactured  into  various  articles  of  wearing 
apparel,  &c. 

GUM-LAC. 

The  improper  name  of  gum-lac  is  given  to  a  concrete 
brittle  substance,  of  a  dark-red  colour,  brought  from  the 
East  Indies,  incrustated  on  the  twigs  of  the  Croton  Lnci- 
ferurn ,  where  it  is  deposited  by  a  small  insect,  at  present 
not  scientifically  known.  It  is  found  in  great  quantities 


238 


CHEMISTRY. 


on  the  uncultivated  mountains  on  both  sides  the  Ganges 
and  is  of  great  use  to  the  natives  in  various  works  of  art, 
as  varnishing,  painting,  dyeing,  &.c.  \Vhen  the  resinous 
matter  is  broken  oh  the  wood  into  small  pieces  or  grains, 
it  is  termed  seed-lac,  and  when  melted  and  formed  into 
flat  plates,  shell-lac.  I  his  substance  is  chielly  employed 
for  making  sealing-wax.  A  tincture  of  it  is  recommended 
as  an  antiscorbutic  to  wash  the  gums. 

GUM  RESINS. 

Gum  resins  are  distinguished  from  common  resins  by 
their  forming  milky  solutions  with  alcohol,  and  by  their 
being  infusible.  Their  solutions  with  alcohol  are  transpa¬ 
rent.  F rankincense,  scammony,  aloes,  and  gum  ammoniac, 
are  gum  resins.  Both  gum  resins  and  balsams  atlord 
tannin  when  treated  with  nitric  acid. 

TAR. 

This  is  obtained  as  a  secondary  product  in  making 
charcoal  of  resinous  woods ;  namely  of  the  pine  and  fir 
trees. 

The  general  process  is  to  mark  out  a  circular  tar 
hearth  in  the  forest,  of  about  30  feet  in  diameter,  which 
is  paved  with  a  slope  towards  its  centre,  or  at  least  form¬ 
ed  of  a  thick  bed  of  well-rammed  clay.  From  near  the 
centre  a  trough  or  covered  gutter  isr  formed,  which  is 
frequently  only  a  tree  split,  hollowed,  and  then  joined 
together  with  clay,  with  which  it  is  also  coated  to  defend 
it  from  the  lire.  I  his  trough  ends  in  a  cistern  sunk  in 
the  ground  to  receive  the  tar  as  it  flows  from  the  trough 

A  pole,  15  or  18  feet  long,  being  stuck  upright  in  the 
centre  of  the  hearth,  the  billets  or  fagots  of  resinous 
wood  are  piled  round  it,  in  a  bed  about  20  feet  in 
diameter.  Lpon  this,  a  bed  of  less  diameter  is  made, 
and  so  on,  decreasing  gradually,  to  form  a  conical  pile; 
which  is  covered  with  fresh-cut  turfs,  having  a  few  open¬ 
ings  round  the  pile,  on  a  level  with  the  ground.  The 
whole  being  left  for  a  day  or  two  to  settle,  the  pole  in 
the  middle  is  withdrawn,  and  the  pile  lighted  at  the  bot- 


ORGANIC  SUBSTANCES. 


239 


tom  holes.  When  the  pile  is  well-lighted,  the  holes  are 
stopped,  and  should  the  fire  appear  by  any  cracks  in  the 
covering,  fresh  turfs  are  laid  to  the  place.  The  third 
day,  the  end  of  the  gutter  is  opened  next  the  cistern, 
which  had  hitherto  been  stopped,  and  the  tar  already 
made,  permitted  to  run  out.  This  opening  is  then  closed 
again,  and  only  opened  two  or  three  times  a  day,  during 
the  remainder  of  the  process. 

The  tar  thus  obtained  generally  requires  to  be  heated 
in  large  iron  pots,  to  drive  away  the  water  and  pyrolig¬ 
neous  acid  that  runs  out  along  with  it,  and  cannot  be 
separated  by  ladling;  and  also  to  allow  the  sand,  and 
other  impurities  which  the  tar,  in  this  rude  process,  has 
acquired,  to  settle,  and  be  thus  separated. 

GREEN  TAR. 

This  is  made  in  the  same  manner  as  common  tar, 
from  the  wood  of  those  trees  which  have  done  yielding 
turpentine  by  incision. 

Tar  is  used  as  a  cheap  varnish  for  wood-work;  also 
as  a  raw  material  to  make  pitch. 

PYROLIGNEOUS  TAR. 

This  is  a  secondary  product,  collected  in  distilling 
wood  which  is  not  of  a  resinous  nature,  or  charcoal  for 
making  gunpowder. 

It  may  be  used  for  the  same  purposes  as  tar;  with 
which,  however,  it  will  not  unite. 

Since  the  use  of  coal  gas  for  illumination,  a  secondary 
product  has  been  obtained,  which  has  partly  superseded 
the  common  coal  tar,  which  has  been  made  in  brick  fur¬ 
naces  since  the  year  1740.  It  may  be  used  for  the  same 
purposes  as  common  tar ;  but  as  some  prejudices  exist 
against  its  use,  it  is  mostly  employed  for  illumination. 

PITCH. 

Two  methods  are  in  general  use  for  making  pitch  ; 
namely,  either  simply  boiling  the  tar  in  large  iron  pots, 
or  setting  it  on  fire,  and  letting  it  burn,  until,  by  dipping 


240 


CHEMISTRY. 


a  stick  into  it,  the  pitch  appears  to  have  acquired  a  pro* 
pei  consistence. 

r wo  barrels  of  the  best  tar,  or  2^  barrels  of  green 
tar,  are  computed  to  make  one  barrel  of  pitch. 

Pitch  is  used  as  a  coarse  varnish  for  ships’  bottoms, 
also,  to  close  the  joints  of  carpenters’  and  coopers’  works 
to  enable  them  to  retain  water. 

BROWN  ROSIN. 

This  is  the  residuum  left  in  the  still  after  turpentine 
has  been  distilled  without  water  for  its  oil,  and  which  is 
run,  or  ladled  out  of  the  still  into  casks,  cut  in  half  foi 
sale. 

Its  colour  is  more  or  less  dark,  sometimes  approaching 
nearly  to  black,  according  to  the  degree  that  the  distil¬ 
lation  has  been  pushed. 

It  is  used  as  the  base  of  many  common  varnishes  and 
cements;  also,  to  sprinkle  on  the  surface  of  metals  that 
are  to  be  joined  with  another  metal,  in  order  to  pro¬ 
mote  their  union.  It  is,  also,  made  with  tallow  into  a 
soap. 

When  melted  with  a  little  vinegar,  to  render  it  clam' 
my,  it  is  used  by  violin  players  to  rub  their  bows. 

YELLOW  ROSIN. 

This  is  made  by  ladling  out  the  brown  rosin  from  the 
stills  into  a  vessel  of  hot  water :  a  violent  efflorescence 
takes  place,  and  the  rosin  absorbs  one-eighth  of  its  weight 
of  water. 

It  is  used  for  the  same  purposes  as  brown  rosin,  but 
is  less  hard,  and,  therefore,  less  adapted  for  cement.  Its 
light  colour,  however,  is  sometimes  advantageous. 


ANIMAL  SUBSTANCES. 


241 


ANIMAL  SUBSTANCES. 

Animal  substances  present  us  with  the  same  constitu¬ 
ent  principles  as  vegetables :  but  the  proportions  of  these 
principles  are  different.  By  destructive  distillation  they 
afford  much  ammonia,  which  is  sparingly  distributed  in 
the  vegetable  kingdom;  they  also  contain  much  nitrogen 
of  which  the  proportion  is  usually  small  among  vegeta 
bles ;  and  they  are  most  abundant  in  phosphorus  ;  while 
ot  carbon  and  hydrogen,  which  are  abundant  in  vegetables, 
they  contain  but  little.  They  are  also  distinguished  from 
vegetables  by  their  undergoing  only  the  putrid  fermenta¬ 
tion,  while  vegetables,  previous  to  this  fermentation, 
undergo  one  of  which  the  product  affords  alcohol,  and 
another  which  affords  vinegar. 

The  distinct  compound  substances  derived  from  animals, 
are  very  numerous ;  we  shall  notice  the  most  important 
of  them. 

GELATINE. 

Gelatine,  or  jelly,  is  supplied  by  all  the  parts  of 
animals,  even  bones,  but  is  most  abundant  in  the  soft  and 
white  parts.  It  is  perfectly  soluble  in  warm  water,  but 
insoluble  in  alcohol,  and  has  little  taste  or  smell ;  on  cool¬ 
ing,  when  not  diffused  in  too  large  a  quantity  cf  water, 
it  has  a  tremulous  consistence,  and  becomes  fluid  by  an 
increase  of  heat.  Gelatine  is  prepared  for  the  table 
from  calves’  feet  and  the  muscular  part  of  animals.  It 
is  a  substance  strongly  tending  to  putrefaction  when  com¬ 
bined  with  water,  and  it  differs  from  vegetable  jelly 
chiefly  in  this  tendency ;  but  if  it  be  concentrated  and 
dried  in  a  stove,  it  may  be  kept  in  a  dry  place  for  many 
years.  In  this  state  it  forms  the  preparation  called 
portable  soup ;  it  is  easily  soluble  in  boiling  water,  and 
a  very  small  quantity  of  it  forms  a  basin  of  "soup. 

When  gelatine  is  obtained  from  the  skin,  cartilages, 
and  refuse  of  animal  matter,  and  reduced  only  to  the 
consistence  of  a  jelly,  it  is  used  in  the  arts  under  the 
21  Q 


242 


CHEMISTRY. 


name  of  size.  When  the  gelatine  is  concentrated  and 
dried,  it  forms  glue.  The  strongest  glue  is  afforded  by 
old  animals.  Isinglass  is  a  glue  which  consists  of  the 
air-bladder  of  the  beluga  ;  a  species  of  fish  plentiful  in 
the  rivers  of  Russia. 

Gelatine  is  dissolved  both  by  acids  and  alkalies 
Tannin  forms  with  it  an  insoluble  compound. 

ALBUMEN. 

Albumen,  or  coagulable  lymph,  exists  in  its  purest 
natural  state  in  the  white  of  eggs,  which  consists  almost 
entirely  of  it;  it  is  also  abundant  in  the  humours  of  the 
eye,  and  the  fluid  of  dropsy.  Its  properties  are  similar 
to  the  albumen  of  vegetables.  It  is  soluble  in  water, 
before  it  has  been  coagulated  by  heat,  but  not  afterwards. 
Alkalies  dissolve  the  coagulum. 

Albumen  is  coagulated  by  acids,  and  in  some  degree 
by  alcohol.  It  speedily  putrefies. 

FIBRIN. 

If  the  muscle  of  an  animal  be  macerated  in  cold 
water,  afterwards  digested  in  alcohol,  and  in  boiling  water, 
to  remove  all  the  parts  soluble  by  these  agents,  a  white, 
insipid,  fibrous  substance  remains,  which  is  called/t&mi. 

Fibrin  forms  the  principal  part  of  the  muscle.  It  is 
insoluble  in  water,  alcohol,  ether,  or  oils ;  it  has  neither 
taste  nor  smell ;  it  contracts  when  heated,  and  by  a 
stronger  heat  is  melted.  It  is  soluble  in  acids  and  alka¬ 
lies,  but  not  in  cold  liquid  ammonia.  Alkalies  precipitate 
it  from  acids  in  flakes,  which  are  soluble  in  hot  water, 
and  resemble  gelatine.  With  nitric  acid,  it  affords  more 
nitrogen  than  any  other  substance.  By  destructive  dis¬ 
tillation,  it  affords  water,  carbonate  of  ammonia,  a  thick, 
heavy,  fetid  oil,  traces  of  acetic  acid,  carbonic  acid,  and 
carburetted  hydrogen.  It  also  contains  some  phosphate 
of  soda  and  of  lime. 

Fibrin  exists  in  blood,  by  which  it  is  deposited  on  the 
muscles.  If  the  clotted  or  coagulated  part  of  blood  be 


ANIMAL  SUBSTANCES. 


243 


tied  up  in  a  linen  cloth,  and  washed  in  water  till  the 
water  ceases  to  receive  either  colour  or  taste  from  it 
fibrin  will  remain  in  the  linen. 

Fibrin  has  a  verv  near  resemblance  to  gluten. 

BONES. 

Bones  derive  solidity  from  the  phosphate  of  lime 
which  forms  a  considerable  part  of  them ;  cartilages 
which  are  bones  in  the  first  part  of  their  formation,  have 
the  properties  only  of  coagulated  albumen.  The  gelatine 
and  fat  combined  with  bones,  impart  toughness  and 
strength,  and  hence,  when  their  quantity  is  diminished  by 
age,  the  bones  are  easily  broken.  One  hundred  parts  of 
ox-bones,  according  to  the  analysis  of  Fourcroy  and 
Vanquelin,  are  composed  of  solid  gelatine  51,  phosphate 
of  lime  37.7,  carbonate  of  lime  10,  phosphate  of  mag¬ 
nesia  1.3. 

The  enamel  of  human  teeth  contains  a  greater  quan¬ 
tity  of  the  phosphate  of  lime,  and  is  destitute  of  gelatine. 
The  shells  of  animals  are  a  species  of  bones ;  they  con¬ 
tain  about  the  same  quantity  of  carbonate  of  lime,  that 
the  bones  of  perfect  animals  contain  of  phosphate  of 
lime. 

HORN. 

Horns,  hoofs,  nails,  and  quills,  differ  but  little  in  their 
chemical  characters ;  they  are  found  to  consist  chiefly 
of  condensed  albumen,  with  some  oil,  and  a  very  small 
proportion  of  gelatine  and  phosphate  of  lime. 

Stag’s  horn  and  ivory  are  nearly  the  same  as  bone, 
and  contain  much  gelatine. 

Hair,  wool,  and  feathers,  differ  but  little  from  each 
other  in  their  composition  ;  one  fourth  of  their  weight 
consists  of  oil,  on  which  their  colour  depends;  they  alford 
besides,  water,  ammonia,  carbon,  silex,  and  iron.  Hair 
is  soluble  in  alkalies,  with  which  it  forms  soap. 

BLOOD. 

Blood,  recently  drawn  from  an  animal,  appears  to  be 
a  thin  and  homogeneous  fluid  ;  but  it  soon  separates  into 


244 


CHEMISTRY. 


two  parts,  the  one  a  coagulated  part,  called  the  crassa- 
vientam ;  the  other  a  fluid,  called  the  serum. 

The  crassamentum  is  of  a  red  colour  ;  it  contains  albu 
men,  iron,  soda,  and  fibrin  ;  the  fibrin  constitutes  its  basis, 
and  may  be  obtained  separately  by  washing  it  in  water. 
It  has  all  the  properties  of  the  fibrin  obtained  from  mus¬ 
cular  fibre.  The  crassamentum  has  a  specific  gravity 
>f  1.245,  whereas,  that  of  blood  is  only  about  1.05. 

Serum  is  of  a  light  greenish  colour.  Its  taste  is 
slightly  saline,  and  it  turns  syrup  of  violets  green ;  this 
property  it  owes  to  the  uncombined  soda  which  it  con¬ 
tains.  It  is  coagulable  by  a  temperature  of  15(5°,  and  is 
then  of  a  greyish  white  colour ;  it,  therefore,  contains  a 
forge  proportion  of  albumen ;  it  also  contains  gelatine, 
hydrosulphuret  of  ammonia,  soda,  muriate  of  soda,  phos¬ 
phate  of  soda,  and  phosphate  of  lime.  Acids  perma¬ 
nently  coagulate  serum  ;  alkalies  increase  its  fluidity ; 
dcohol  coagulates  it,  but  the  coagulum  is  soluble  in 
water. 

When  the  blood,  after  circulating  through  the  body, 
has  arrived  at  the  lungs  in  its  way  to  the  heart,  it  has 
acquired  a  dark  colour;  but  when,  in  the  lungs,  it  has 
’  been  exposed  to  atmospheric  air,  it  absorbs  oxygen,  with 
a  minute  portion  of  nitrogen,  and  parts  with  carbon; 
the  consequence  of  this  operation  is  its  acquiring  an 
increase  of  heat,  and  a  fine  crimson  colour. 

MILK. 

Milk  is  usually  considered  as  consisting  of  three  parts  ; 
the  caseous,  butyraceous,  and  serous,  which,  upon  its 
being  allowed  to  stand  in  an  open  vessel,  spontaneously 
separate  from  each  other. 

The  butyraceous  part,  or  cream,  rises  to  the  surface, 
and,  when  designed  to  furnish  butter,  it  is  skimmed  oil 
and,  being  put  into  a  vessel  in  which  it  can  be  rapidly 
agitated,  the  butter  separates  from  it.  Butter,  when 
fluid,  is  transparent;  but  it  becomes  opaque,  as  it  cools 
and  hardens.  The  butter  of  cows’  milk  becomes  harder 
than  that  of  any  other  animal. 


ANIMAL  SUBSTANCES 


245 


The  caseous,  or  cheesy  part  of  milk  is  obtained  by  co 
agulating  milk  with  an  acid.  For  this  purpose,  in  pre¬ 
paring  cheese  from  cows’  milk,  rennet  is  used  which  is 
the  stomach  of  a  calf  in  which  milk  has  soured.  The 
coaguium  is  separated  from  the  fluid  part,  to  make 
cheese. 

After  the  whole  of  the  matter  which  is  capable  of  co¬ 
agulating  is  separated  from  milk,  the  serous,  or  watery 
part  only  remains :  but  rennet,  from  its  slight  acidity, 
does  not  make  a  complete  separation.  The  fluid,  there¬ 
fore,  remaining  after  rennet  has  been  used,  still  contains 
saccharine  particles  and  curd,  and,  under  the  name  of 
whey,  is  used  as  a  wholesome  beverage.  The  serum  ob¬ 
tained  by  the  spontaneous  decomposition  of  milk  is  acidu¬ 
lous,  and  totally  devoid  of  nourishment. 

If  sweet  whey  be  evaporated  to  the  consistence  of 
honey,  and  afterwards  dried  in  the  sun,  a  solid  substance 
is  obtained,  which  is  called  sugar  of  milk.  If  the  sugar 
pf  milk  thus  prepared  be  dissolved  in  water,  it  may  be 
clarified  by  whites  of  eggs,  and  will  afford  white  crystals, 
after  being  evaporated  to  the  consistence  of  a  syrup. 
Sugar  of  milk  is  soluble  in  three  or  four  parts  of  water: 
its  taste  is  slightly  sweet ;  and  it  yields,  by  distillation, 
nearly  the  same  products  as  other  sugar. 

Milk  is  capable  of  undergoing  the  vinous  fermentation, 
and,  consequently,  of  affording  a  spiritous  liquor.  Marco 
Polo,  who  wrote  in  the  thirteenth  century,  asserted,  that 
liquor  prepared  from  mares’  milk,  by  the  Tartars, 
might  be  taken  for  white  wine.  If  milk  be  deprived 
of  its  cream,  it  will  not  afford  a  spiritous  fluid. 

Thenard  gives  the  following  as  the  component  parts 
of  milk  ;  1,  water  ;  2,  acetous  acid  ;  3,  caseous  ;  4,  buty- 
raceous ;  5,  saccharine ;  and  0,  by  extractive  matter ; 
7,  8,  muriate  of  soda,  and  potass;  9,  sulphate  of  potass; 
10,  11,  phosphates  of  lime  and  magnesia.  The  acid  here 
called  the  acetous,  is  now  found  to  have  different  pro¬ 
perties,  and  is  called  the  lactic  acid.  (See  Lactic  acid.) 
The  milk  of  different  animals  in  its  composition — asses’ 
mares’  and  womens’  milk— -are  the  most  saline  and 
21  * 


246 


CHEMISTRY. 


sdrous  ;  cows’,  goats’,  and  sheep’s,  contain  the  most  of  the 
caseous  and  butyraceous  parts. 

CARTILAGE. 

A  white,  elastic,  glistening  substance,  growing  to  the 
bones,  and  commonly  called  gristle.  Cartilages  are  di¬ 
vided,  by  anatomists,  into  obducent,  which  cover  the 
moveable  articulationsof  bones;  and  inter  articular,  which 
are  situated  between  the  articulations  and  uniting  car 
tilages,  which  unite  one  bone  with  another.  Their  use 
is,  to  facilitate  the  motions  of  bones,  or  to  connect  them 
together. 

The  chemical  analysis  of  cartilage  affords  one-third 
the  weight  of  the  bones,  when  the  calcareous  salts  are 
removed  by  digestion  in  dilute  muriatic  acid.  It  resem¬ 
bles  coagulated  albumen.  Nitric  acid  converts  it  into 
gelatine.  With  alkalies,  it  forms  an  animal  soap.  Carti¬ 
lage  is  the  primitive  paste  into  which  the  calcareous  salts 
are  deposited  in  the  young  animal.  In  the  disease,  rick¬ 
ets,  the  early  matter  is  withdrawn  by  morbid  absorption, 
and  the  bones  return  into  the  state  nearly  of  flexible 
cartilage.  Hence  arise  the  distortions  characteristic  of 
this  disease. 

ANIMAL  GLUTEN. 

This  substance  constitutes  the  basis  of  the  fibres  of 
all  solid  parts.  It  resembles  in  its  properties,  the  gluten 
of  vegetables. 

GLUE. 

An  inspissated  jelly,  made  from  the  parings  of  hides, 
and  other  offals,  by  boiling  them  in  water,  straining 
through  a  wicker  basket,  suffering  the  impurities  to  sub¬ 
side,  and  then  boiling  it  a  second  time.  The  articles 
should  rirst  be  digested  in  lime-water,  to  cleanse  them 
from  grease  and  dirt,  then  steeped  in  water,  stirring  them 
well  from  time  to  time;  and,  lastly,  laid  in  a  heap  to 
have  the  water  pressed  out,  before  they  are  put  into  the 
boiler.  Some  recommend  that  the  water  should  be  kept 


BITUMINOUS  SUBSTANCES. 


247 


as  nearly  as  possible  to  a  boiling  heat,  without  suffering 
it  to  enter  into  ebullition.  In  tiffs  state,  it  is  poured  into 
flat  frames  or  moulds,  then  cut  into  square  pieces  when 
congealed,  and,  afterwards,  dried  in  a  coarse  net.  It  is 
said  to  improve  by  age  ;  and  that  glue  is  reckoned  the 
best,  which  swells  considerably,  without  dissolving,  by 
three  or  four  days’  infusion  in  cold  water,  and  recovers 
its  former  dimensions  and  properties  by  drying.  Shreds, 
or  parings  of  vellum,  parchment,  or  white  leather,  make 
a  clear,  and  almost  colourless  glue.  (See  Mechanical 
Exercises.) 

BITUMINOUS  SUBSTANCES. 

ASPHALTUM. 

Asphaltum  is  a  smooth,  hard,  brittle,  black  or  brown 
sulistance,  which  breaks  with  a  polish,  melts  easily  when 
heated,  and  when  pure  burns  without  leaving  any  ashes. 
It  is  found  in  a  soft  or  liquid  state  on  the  surface  of  the 
Dead  Sea,  but  by  age  grows  dry  and  hard.  The  same 
kind  of  bitumen  is  likewise  found  in  the  earth  in  other 
parts  of  the  world;  in  China,  America,  particularly  in 
the  Island  of  Trinidad;  and  in  some  parts  of  Europe,  as 
the  Carpathian  hills,  France,  Neufchatel,  &c.' 

According  to  Neumann,  the  asphaltum  of  the  shops  is 
a  very  different  compound  from  the  native  bitumen;  and 
varies,  of  course,  in  its  properties,  according  to  the  nature 
of  the  ingredients  made  use  of  in  forming  it.  On  this 
account,  and  probably  from  other  reasons,  the  use  of 
asphaltum,  as  an  article  of  the  materia  medica ,  is  totally 
laid  aside. 

The  Egyptians  used  asphaltum  in  embalming,  under 
the  name  of  mumia  mineralis,  for  which  it  is  well 
adapted.  It  was  used  for  mortar  at  Babylon. 

BITUMENS. 

This  term  includes  a  considerable  range  of  inflam¬ 
mable  mineral  substances,  burning  with  flame  in  the  open 


248 


CHEMISTRY. 


air.  They  are  of  different  consistency,  from  a  thin  fluid 
to  a  solid ;  but  the  solids  are  for  the  most  part  liquefiable 
at  a  moderate  heat.  The  fluid  are, 

1.  Naphtha,  a  fine,  white,  thin,  fragrant,  colourless  oil, 
which  issues  out  of  while,  yellow,  or  black  clays  in 
Persia  and  Media.  This  is  highly  inflammable,  and  is 
decomposed  by  distillation.  It  dissolves  resins,  and  the 
essential  oils  of  thyme  and  lavender ;  but  is  not  itself 
soluble  either  in  alcohol  or  ether.  It  is  the  lightest  of 
all  the  dense  fluids,  its  specific  gravity  being  0.708. 

2.  Petroleum,  which  is  from  a  yellow,  reddish,  brown, 
greenish,  or  blackish  oil,  found  dropping' from  rocks,  or 
issuing  from  the  earth,  in  the  duchy  of  Modena,  and  in 
various  other  parts  of  Europe,  and  Asia.  This,  like¬ 
wise,  is  insoluble  in  alcohol,  and  seems  to  consist  of 
naphtha,  thickened  by  exposure  to  the  atmosphere.  It 
contains  a  portion  of  the  succinic  acid. 

3.  Barbadoes  tar,  which  is  a  viscid,  brown,  or  black 
inflammable  substance,  insoluble  in  alcohol,  and  contain¬ 
ing  the  succinic  acid.  This  appears  to  be  the  mineral 
oil  in  its  third  State  of  alteration. 

The  solid  are,  1.  Asphaltum,  mineral  pitch,  of  which 
there  arc  three  varieties :  the  cohesive ;  the  semi-com¬ 
pact,  maltha;  the  compact,  or  asphaltum.  These  are 
smooth,  more  or  less  hard  or  brittle,  inflammable  sub¬ 
stances,  which  melt  easily,  and  burn  without  leaving  any 
or  but  little  ashes  if  they  be  pure.  They  are  slightly 
and  partially  acted  on  by  alcohol  and  ether.  (See 
Asphaltum.) 

2.  Mineral  tallow,  which  is  a  white  substance  of  the 
consistence  of  tallow,  and  as  greasy,  although  more 
brittle.  It  was  found  in  the  sea  on  the  coast  of  Finland, 
n  the  year  1730;  and  is  also  met  with  in  some  rocky 
parts  of  Persia.  It  is  near  one-fifth  lighter  than  tallow 
burns  with  a  blue  flame  and  a  smell  of  grease,  leaving  a 
black  viscid  matter  behind,  which  is  more  difficultly 
consumed. 

3.  Elastic  bitumen,  or  mineral  caoutchouc,  of  which 
there  are  two  varieties.  Besides  these,  there  are  other 


BITUMINOUS  SUBSTANCES. 


249 


bituminous  substances,  as  jet  and  amber,  which  approach 
the  harder  bitumens  in  their  nature;  and  all  the  varieties 
of  pit-coal,  and  the  bituminous  schistres,  or  shale,  which 
contain  more  or  less  of  bitumen  in  their  composition. 

AMBER. 

A  beautiful  bituminous  substance,  which  takes  a  good 
polish,  and  after  a  slight  rubbing,  becomes  so  electric,  as 
to  attract  straws  and  small  bodies.  Amber  is  a  hard, 
brittle,  tasteless  substance,  sometimes  perfectly  transpa¬ 
rent,  but  mostly  semi-transparent  or  opaque,  and  of  a 
glossy  surface;  it  is  found  of  all  colours,  but  chiefly 
yellow  or  orange,  and  often  contains  leaves  or  insects 
'its  specific  gravity  is  from  1.005  to  1.100;  its  fracture  i‘ 
even,  smooth,  and  glossy ;  it  is  capable  of  a  fine  polish 
and  becomes  electric  by  friction  ;  when  rubbed  or  heated, 
it  gives  a  peculiar  agreeable  smell,  particularly  when  it 
melts,  that  is  at  550°  of  Fahrenheit,  but  then  it  loses  its 
transparency ;  projected  on  burning  coals,  it  burns  with 
a  whitish  flame,  and  a  whitish  yellow  smoke,  but  gives 
very  little  soot  and  leaves  brownish  ashes ;  it  is  insoluble 
in  water  and  alcohol,  though  the  latter,  when  highly 
rectified,  extracts  a  reddish  colour  from  it;  but  is  soluble 
in  the  sulphuric  acid,  \Vhich  then  acquires  a  reddish 
purple  colour,  and  is  precipitable  from  it  by  water.  No 
other  acid  dissolves  it,  nor  is  it  soluble  in  essential  or 
expressed  oils,  without  some  decomposition  and  long  di¬ 
gestion  ;  but  pure  alkali  dissolves  it.  By  distillation  h 
affords  a  small  quantity  of  water,  with  a  little  acetous- 
acid,  an  oil,  and  a  peculiar  acid. 

Amber  is  met  with  plentifully  in  regular  mines  in  some 
parts  of  Prussia.  The  upper  surface  is  composed  of 
sand,  under  which  is  a  stratum  of  loam,  and  under  this 
a  bed  of  wood,  partly  entire,  but  chiefly  mouldered  or 
changed  into  a  bituminous  substance.  Under  the  wood 
is  a  stratum  of  sulphuric  or  rather  aluminous  mineral 
in  which  the  amber  is  found.  Strong  sulphuric  exhala 
tions  are  often  perceived  in  the  pits.  Detached  piec<e* 
are  also  found  occasionally  on  the  sea  coast  in  vari»  * 


250 


CHEMISTRY. 


countries.  It  has  been  found  in  gravel  beds  near  London, 
In  the  Royal  Cabinet  at  Berlin  there  is  a  mass  of  18lbs. 
weight,  supposed  to  be  the  largest  ever  found.  Jussieu 
asserts,  that  the  delicate  insects  in  amber,  which  prove 
the  tranquillity  of  its  formation,  are  not  European. 
Hany  has  pointed  out  the  following  distinction  between 
mellite  and  copal,  the  bodies  which  most  closely  resem¬ 
ble  amber.  Mellite  is  infusible  by  heat.  A  bit  of  copal 
heated  at  the  end  of  a  knife  takes  fire,  melting  into 
drops,  which  flatten  as  they  fall ;  whereas  amber  burns 
with  spitting  and  frothing ;  and  when  its  liquified  parti¬ 
cles  drop,  they  rebound  from  the  plane  which  receives 
them.  The  origin  of  amber  is  at  present  involved  in 
perfect  obscurity,  though  the  rapid  progress  of  vegetable 
chemistry  promises  soon  to  throw  light  on  it.  Various 
frauds  are  practised  with  this  substance.  Neumann 
states  as  the  common  practice  of  workmen,  the  two 
following:  The  one  consists  in  surrounding  the  amber 
with  sand  in  an  iron  pot,  and  cementing  it  with  a  gradual 
fire  for  forty  hours,  some  small  pieces  placed  near  the 
sides  of  the  vessel  being  occasionally  taken  out  for  judging 
of  the  effect  of  the  operation :  the  second  method,  which 
he  says  is  that  most  generally  practised,  is  by  digesting 
and  boiling  the  amber  about  twenty  hours  with  rapeseed 
oil,  by  which  it  is  rendered  both  clear  and  hard. 

W  erner  has  divided  it  into  two  sub-species,  the  white 
and  the  yellow ;  but  there  is  little  advantage  in  the  dis¬ 
tinction.  Its  ultimate  constituents  are  the  same  with 
those  ot  vegetable  bodies  in  general ;  viz.  carbon,  hydro¬ 
gen,  and  oxygen. 

In  the  second  volume  of  the  Edinburgh  Philosophical 
Journal,  Dr.  Brewster  has  given  an  account  of  some 
optical  properties  of  amber,  from  which  he  considers  it 
established  beyond  a  doubt,  that  amber  is  an  indurated 
vegetable  juice  ,*  and  that  the  traces  of  a  regular  struc¬ 
ture,  indicated  by  its  action  upon  polarized  light,  are 
not  the  effect  of  the  ordinary  laws  of  crystallization  bv 
which  mellite  has  been  formed,  but  are  produced  by  the 
same  causes  which  influence  the  mechanical  condition  of 


OF  CRYSTALLIZATION. 


251 


gum-arabic,  and  other  gums,  which  are  known  to  be 
formed  by  the  successive  deposition  and  induration  of 
vegetable  fluids. 


OF  CRYSTALLIZATION. 

Crystals  are  aggregations  of  the  particles  of  bodies, 
which  have  been  spontaneously  disposed  in  a  regular 
form;  and  crystallization  denotes  the  act  of  their  forma¬ 
tion.  According  to  the  strict  meaning  of  the  word,  a 
crystal  should  be  transparent,  as  well  as  symmetrical  in 
its  form  ;  but  it  is  now  extended  to  opaque  substances,  and 
regularity  of  form  is  its  leading  characteristic. 

Crystallization  is  of  two  kinds,  the  dry  and  the  humid  ; 
dry  crystallization  refers  to  metals  and  other  substances 
which  cannot  combine  with  water ;  the  humid  crystalliza¬ 
tion  refers  to  fluids  and  gases  holding  solids  in  solution ; 
and  which  never  affords  crystals  but  what  contain  more 
or  less  water. 

The  water  combined  with  a  crystal  is  called  its  water 
of  crystallization.  No  crystals  are  transparent  unless 
they  contain  water.  The  water,  in  thus  combining  with 
bodies,  loses  its  caloric  of  fluidity. 

The  same  substance,  under  the  same  circumstances, 
always  affords  crystals  of  the  same  figure ;  but  except¬ 
ing  the  circumstances  which  modify  the  natural  process 
of  crystallization,  all  the  differences  observed  in  the  forms 
of  crystals,  are  attributable  to  differences  in  the  forms 
of  the  integral  particles  of  the  crystals. 

Crystallization  cannot  take  place  unless  the  particles 
of  bodies  be  at  liberty  to  arrange  themselves  according  to 
their  peculiar  attractions.  Hence  it  is  necessary,  either 
that  they  be  in  a  state  of  solution,  or  suspended  in  a 
fluid,  in  a  state  of  extremely  minute  division,  or  in  fusion. 
It  has  not  been  decisively  proved  that  mere  suspension 
will  produce  such  a  regular  arrangement  of  particles  as 
can  be  called  crystallization ;  but  admitting  this  to  be 


252 


CIIEM1STUY. 


possible,  the  division  of  the  particles  which  form  th« 
crystals  must  be  carried  so  far  as  scarcely  to  differ  from 
solution,  and  the  same  explanation  will  aoply  as  to  solu¬ 
tion. 

Suppose  we  have  a  saturated  solution  of  common  salt 
in  water ;  the  particles  of  the  salt  are  so  completely  dis- 
peised  through  the  water,  and  probably  so  far  removed 
from  each  other,  that  the  particles  of  the  water  exert  a 
stronger  attraction  on  them  than  they  exert  on  each 
other:  the  solution,  therefore,  remains  perfect;  but  let 
some  of  the  water  be  evaporated  ;  it  is  now  evident  that 
as  the  same  quantity  of  salt  is  contained  in  a  less  compass, 
the  particles  of  the  salt  must  have  approximated  each 
other,  and  are  within  the  sphere  of  each  other’s  attrac¬ 
tion .  they,  therefore,  aggregate  and  form  crystals,  until 
the  solution  is  of  the  same  intensity  as  at  first.  If  the 
evaporation  be  resumed,  more  crystals  are  formed  in  the 
>ame  manner,  until  at  last,  by  the  evaporation  of  the 
whole  of  the  water,  the  crystals  are  obtained  dry. 

The  crystallization  of  a  metal  is  not  essentially  differ¬ 
ent  from  an  aqueous  crystallization.  The  metal  may  be 
regai ded  as  held  in  solution  by  caloric;  and,  as  the  ca¬ 
loric  of  fluidity  is  withdrawn  by  the  cooling  of  the  metal, 
the  case  is  correspondent  to  that  of  the  reduction  of  the 
quantity  of  water  in  the  aqueous  solution,  and  the  parti¬ 
cles  will  arrange  themselves  according  to  their  form. 
It  must  be  obvious,  that  if  the  particles  of  the  metal, 
or  of  the  solid  in  solution,  consist  of  cubes,  they  will  ag¬ 
gregate  in  forms  of  one  description ;  and,  if  they  are 
tetrahedrons,  they  must  place  themselves  upon  each 
other  in  another. 

A  fluid  which  has  furnished  all,  or  the  greater  part  of 
the  crystals  that  can  be  obtained  from  it,  is  called  mother 
water. 

In  general,  fluids  at  a  boiling-heat  hold  in  solution  a 
much  larger  portion  of  any  matter  than  when  cold,  be¬ 
cause  caloric  has  a  powerful  effect  in  lessening  the 
attraction  of  aggregation,  and  preventing  particles  which 
are  very  near  from  combining.  Common  salt  is,  how 


CRYSTALLIZATION. 


253 


-»ver,  an  instance  of  a  common  salt  which  is  nearly  as 
soluble  in  cold,  as  in  hot  water :  but  it  appears  to  be  a 
general  law,  that  salts  of  this  kind  require  but  a  small 
quantity  of  the  water  of  crystallization. 

Salts  which  acquire  moisture  from  the  atmosphere,  so 
as  to  become  fluid  or  pulpy,  are  said  to  be  deliquescent : 
when  they  lose  their  crystalline  form  in  the  air,  and  yet 
remain  dry  and  powdery,  it  is  because  their  water  of 
crystallization  has  been  abstracted ;  and  they  are  said  to 
be  efflorescent. 

A  salt  is  deliquescent,  when  it  has  a  greater  attrac¬ 
tion  for  water  than  the  air;  as  it  will,  in  that  case,  take 
water  from  the  air :  a  salt  is  efflorescent,  when  it  has 
a  less  attraction  for  water  than  the  air  ;  for  the  air  will 
then  abstract  water  from  it.  When  the  salt  has  the 
same  attraction  for  water  with  the  air,  it  will  suffer  no 
change. 

The  slower  the  crystallization,  the  larger,  the  harder, 
the  more  regular  and  transparent,  the  crystals  which 
are  formed.  A  rapid  evaporation  of  a  solution,  there¬ 
fore,  produces  imperfect  crystals,  the  particles  not  having 
time  to  assume  the  exact  arrangement  to  which  they  are 
naturally  disposed. 

Crystallization  is  promoted  when  the  solution  is  fur¬ 
nished  with  some  point  at  which  it  may  commence. 

In  a  saturated  solution  which  exhibits  no  signs  of  crys¬ 
tallization,  crystals  will  soon  be  observed,  if  a  thread  be 
stretched  through  it.  But  if,  instead  of  any  foreign  mat¬ 
ter,  a  crystal  of  substance  in  solution  be  introduced,  the 
crystallization  is  still  further  promoted.  Upon  this  fact, 
Le  Blanc  founded  a  method  of  obtaining  very  large  and 
perfect  crystals.  He  selected  the  largest  and  most  per¬ 
fect  crystals  of  salt  recently  formed,  and  put  them  into  a 
saturated  solution  of  the  same  salt.  As  the  side  of  a 
crystal  in  contact  with  the  vessel  receives  no  increase, 
they  were  turned  daily.  After  a  certain  time,  the  largest 
and  most  regular  crystals  thus  obtained  were  employed 
as  the  nucleus  ff  still  larger  crystals,  by  a  repetition  of 
the  process. 

22 


254 


CHEMISTRY. 


Kirwan  observed,  that  if  two  salts  be  held  in  solution 
by  the  same  fluid,  a  crystal  of  either  will  cause  that  salt 
to  crystallize  which  is  of  the  same  kind  as  itself. 

Crystallization  goes  on  but  very  slowly  in  closed  ves 
sels;  and,  in  most  instances,  wholly  stops":  but  Dr.  Hig¬ 
gins  inferred,  from  his  experiments,  that  the  atmosphere 
only  facilitates  the  process  in  consequence  of  its  pressure ; 
and,  therefore,  a  sufficient  column  of  mercury,  or  any 
ther  pressure,  has  the  same  effect.  Perhaps  the  ex¬ 
periment  has  not  been  tried  in  a  proper  manner:  the 
pressure  upon  the  surface  of  a  fluid,  in  a  closed  vessel 
containing  air,  is  not  less  than  when  that  vessel  is  un¬ 
covered. 

1  he  action  of  light  has  the  effect  of  impeding  and  dis¬ 
turbing  crystallization:  and  crystals  are,  therefore, 
larger,  and  more  regular,  when  formed  in  the  dark. 

A  very  singular  discovery  was  accidentally  made  by 
Ifany,  respecting  the  elementary  forms  of  crystals. 
Happening  to  take  up  a  hexangular  prism  of  calcareous 
spar,  which  had  been  detached  from  a  group  of  the 
same  kind,  he  observed  that  a  part  of  the  crystal  was 
wanting,  and  yet  that  it  presented  a  smooth  surface. 
Attempting  to  detach  a  segment  from  the  contiguous 
edge,  he  could  not  succeed;  but  the  ore  next  it  was 
easily  divided.  Proceeding  thus  to  divide  the  crystals 
mechanically,  in  such  a  way  that  the  separation  was 
easy,  and  left  smooth  surfaces,  and  which  did  not  hap¬ 
pen  unless  in  directions  parallel  to  the  first  fracture,  he 
found  that  the  crystal  changed  its  form  as  parts  of  it 
were  separated,  until  at  length  it  acquired  a  form  that 
remained  mathematically  the  same  after  any  subsequent 
sections.  On  trying  the  experiment,  he  found  that  other 
crystals  of  the  same  spar  were  reducible  to  the  same 
unalterable  form;  and  that  crystals  of  other  bodies 
were  also  reducible  to  fixed  forms,  of  one  kind  or  an¬ 
other.  I  hesc  fixed  forms,  therefore,  he  denominates 
the  primitive  forms  of  the  crystals;  and  the  other 
forms  which  crystals  assume,  lie  calls  their  secondary 
forms. 


COMBUSTION. 


255 


The  primitive  form  of  a  fiuate  of  iron,  Hany  found 
o  be  an  octahedron  ;  of  sulphate  of  barytes,  a  prism, 
with  rhombqidal  bases ;  of  corundam,  a  rhomboid, 
somewhat  acute;  of  beryl,  an  hexahedral  prism;  of 
blend,  a  dodecahedron,  with  rhomboidal  sides. 

Pursuing  the  path  which  these  discoveries  pointed  out, 
with  a  rare  combination  of  industry  and  ingenuity,  he 
succeeded  in  delineating  a  system  of  crystalography, 
which,  though  yet  in  its  infancy,  bears  the  strongest  indi¬ 
cations  of  remaining  consistent  with  the  phenomena  of 
nature,  and,  therefore,  of  obtaining  a  permanent  recep¬ 
tion  in  science. 

OF  COMBUSTION. 

Combustion  is  the  union  of  a  body  with  oxygen  accom¬ 
panied  by  the  evolution  of  light  and  heat;  and,  there¬ 
fore,  every  body  which  is  capable  of  forming  this  union, 
is  called  a  combustible. 

Oxygen  is  retained  in  the  gaseous  state  by  the  large 
quantity  of  caloric  with  which  it  is  combined,  and  for 
which  it  has  a  strong  attraction;  but  if  any  substance 
be  presented  to  the  oxygen  gas,  that  has  a  stronger 
attraction  for  oxygen  than  oxygen  has  for  caloric,  the 
consequence  is,  that  the  oxygen  gas  is  decomposed,  its 
particles  unite  with  the  substance  thus  presented  to  it, 
and  a  great  part  of  the  caloric  being  then  left  in  an 
uncombined  state,  recovers  the  properties  which  are 
peculiar  to  it  in  that  state,  that  is,  it  assumes  the  appear¬ 
ance  of  tire.  The  heat  thus  produced  is  the  more 
intense,  the  greater  the  quantity  of  caloric  which  is 
liberated  in  a  given  compass  and  time  ;  and  these  cir¬ 
cumstances  are  dependent  upon  the  strength  of  the 
affinity  between  oxygen  and  the  substance  which  sepa¬ 
rates  it  from  caloric,  and  the  quantity  of  caloric  required 
to  saturate  the  product  of  combustion. 

At  the  ordinary  temperature  of  the  atmosphere,  bodies 
bavc  either  no  affinity  for  oxygen,  or  usually  a  very  weak 
ne  •  hence  they  suffer  no  change,  or  the  change  wnich 


256 


CHEMISTRY. 


does  take  place  is  so  slow,  that  though  a  combustion  in 
effect,  it  is  not  called  by  that  name,  because  neither  light 
nor  heat  are  perceptible  to  the  senses. 

When  the  temperature  of  a  combustible  is  raised,  its 
affinity  for  oxygen  is  increased ;  and  when  it  is  raised  to 
a  certain  point,  which  varies  according  to  the  nature  of 
the  substance,  the  affinity  becomes  very  strong,  the  com¬ 
bustion  is  consequently  rapid  and  brilliant,  taking,  accord¬ 
ing  to  the  phenomena  it  presents,  the  name  of  ignition 
inflammation,  decrepitation,  detonation,  or  fulmination. 

Light  appears  to  form  a  component  part  of  all  com¬ 
bustible  bodies,  and  to  enter,  as  well  as  caloric,  into  the 
composition  of  oxygen  itself.  Hence,  when  oxygen  by 
combustion  enters  into  a  new  combination,  part  at  least 
if  the  light  held  both  by  it  and  the  combustible,  is  dis¬ 
engaged  and  flies  off,  as  well  as  the  caloric.  In  general 
it  appears  evident,  that  the  light  is  furnished  by  the  com¬ 
bustible,  because  the  light  furnished  by  different  com 
bustibles  is  of  different  colours,  and  the  quantity  of  it  is 
by  no  means  proportionate  to  the  quantity  of  oxygen 
consumed.  For  example,  hydrogen  in  combustion  com¬ 
bines  with  a  greater  quantity  of  oxygen  than  any  other 
body  ;  but  the  light,  afforded  is  inconsiderable. 

Although  the  light  furnished  by  combustion  is  not  pro¬ 
portionable  to  the  quantity  of  oxygen  which  enters  into 
combination,  and  therefore  is  evidently  not  wholly  fur¬ 
nished  by  the  oxygen,  yet  the  case  is  the  reverse  with 
the  caloric,  evolved.  The  combustion  of  those  bodies 
which  combine  with  the  greatest  quantity  of  oxygen, 
always  furnishes  the  greatest  quantity  of  caloric,  and 
therefore  the  combustion  of  hydrogen  furnishes  the  most 
intense  heat  that  can  be  produced,  until  some  other  sub¬ 
stance  shall  be  found  which  combines  with  a  greater 
quantity  of  oxygen. 

Another  proof  that  the  chief  part  of  the  caloric  ex¬ 
tricated  during  combustion  is  furnished  by  the  oxygen, 
which  when  it  ceases  to  be  a  gas,  has  no  longer  occasion 
for  it,  is,  that  when  the  oxygen  is  in  combination  with  a 
fluid,  a  combustible  substance,  for  example,  a  metal,  will 


OF  COMBUSTION. 


257 


aostract  it  from  the  fluid,  but  the  usual  phenomena  of 
combustion  do  not  appear,  although  the  combination  with 
oxygen  is  so  rapid,  that  if  the  same  quantity  of  oxygen 
had  been  derived  from  a  gas,  in  th^  same  time,  these 
phenomena  would  have  been  exhibited  with  considerable 
splendour. 

Bodies  which  have  been  once  thoroughly  burnt,  which 
is  only  another  way  of  expressing  that  they  are  saturated 
with  oxygen,  are  incapable  of  undergoing  combustion 
again,  until  some  part  or  all  of  their  oxygen  is  abstracted. 
To  deprive  them  of  their  oxygen  is  virtually  to  unburn 
them  ;  and  when  no  part  of  a  combustible  has  been  dis¬ 
sipated,  but  only  changed  by  the  new  combination,  the 
abstraction  of  the  oxygen  absorbed  restores  its  pristine 
properties.  This  is  the  case  with  metals,  which  acquire 
by  combustion  a  weight  equal  to  the  oxygen  combined 
with  them,  and  of  course  lose  that  acquired  part  of  their 
weight  when  the  oxygen  which  constitutes  it  is  with¬ 
drawn;  but  vegetables  and  other  combustible  matters 
containing  many  volatile  parts,  when  burnt  in  the  open 
air,  have  these  parts  dissipated,  and  therefore  the  pro¬ 
ducts  they  aflord  after  combustion,  weigh  considerably 
less  than  the  vegetables  themselves,  as  they  only  consist 
of  those  parts  which  cannot  be  converted  into  gas. 

We  have  stated  that  many  substances,  by  their  union 
with  oxygen  in  combustion,  are  converted  into  acids  ; 
when  this  happens,  the  combustible  is  said  to  be  oxygen¬ 
ized  ;  when  the  product  of  combustion  is  not  an  acid,  it 
is  called  an  oxide,  and  the  combustible  is  said  to  be 
oxidized. 

The  experiments  which  have  proved  the  alkalies  and 
earths  to  be  metallic  oxides,  have  tended  materially  to 
establish  the  conclusion,  that  all  substances  are  either 
combustible,  or  combined  with  oxygen  to  the  point  of 
saturation  ;  and  if  this  be  maintained,  oxygen  must,  like 
caloric,  have  an  affinity  for  every  substance  existing, 
22*  B, 


ELECTRICITY. 


A  property  which  certain  bodies  possess  when  rubbed, 
neated,  or  otherwise  excited,  whereby  they  attract  re¬ 
mote  bodies,  and  frequently  emit  sparks,  or  streams  of 
light. 

Abstract  of  Electricity. 

1.  Electricity  is  supposed  to  be  a  fluid,  which  repel 
its  own  particles,  but  attracts  all  other  matter. 

2.  That  portion  of  electricity  which  every  body  is  sup¬ 
posed  to  contain,  is  called  its  natural  share. 

3.  When  a  body  is.possessed  of  either  more  or  less  than 
its  natural  share,  it  is  said  to  be  electrified  or  charged. 

4.  If  it  possesses  more  than  its  natural  share,  it  is  said 
to  be  positively  electrified  :  if  it  contains  less  than  its 
natural  share,  it  is  said  to  be  negatively  electrified. 

5.  Bodies  through  which  the  electric  fluid  passes  free¬ 
ly,  are  called  conductors ,  or  non-electrics.  Those  bodies 
which  oppose  the  passage  of  electricity,  are  called  non¬ 
conductors,  or  electrics. 

G.  Glass,  and  some  other  bodies,  which  are  non-con¬ 
ductors  at  common  temperature,  become  conductors, 
when  very  hot. 

7.  The  equilibrium  of  the  electric  fluid  is-  disturbed  by 
the  friction  of  bodies  against  each  other;  and  electricity 
is  then  said  to  b e  produced,  or  excited. 

8.  Electricity  is  excited  in  the  greatest  quantity  by 
the  friction  of  conductors  and  non-conductors  against 
sach  other. 

9.  The  same  substance,  excited  by  a  different  rubber, 
will  alternately  be  electrified  positively  and  negatively. 

10.  Two  bodies,  both  positively,  or  both  negatively 
electrified,  repel  each  other;  whereas,  if  one  body  be 
positive,  and  the  other  negative,  they  will  attract  each 
other. 

11.  Upon  this  principle  are  constructed  electrometers, 
or  instruments  for  ascertaining  whether  bodies  are  elec¬ 
trified  or  not. 


(258) 


ELECTRICITY. 


259 

12.  If  a  body,  containing  only  its  natural  share  of 
electricity,  be  presented  sufficiently  near  to  a  body  elec¬ 
trified  positively  or  negatively,  a  quantity  of  electricity 
will  force  itself  through  the  air,  from  the  latter  to  the 
former,  appearing  in  the  form  of  a  spark. 

13.  When  two  bodies  approach  each  other  sufficiently 
near,  one  of  which  is  electrified  positively,  and  the  other 
negatively,  the  superabundant  electricity  rushes  vio¬ 
lently  from  one  to  the  other,  to  restore  the  equilibrium 
between  them.  This-  effect  also  takes  place,  if  the  two 
bodies  be  connected  by  a  conducting  substance. 

14.  If  an  animal  be  placed  so  as  to  form  part  of  this 
circuit,  the  electricity,  in  passing  through  it,  produces 
a  sudden  effect  upon  it,  which  is  called  the  electric 
shock. 

15.  The  motion  of  electricity,  in  passing  from  a  posi¬ 
tive  to  a  negative  body,  is  so  rapid,  that  it  appears  to  be 
instantaneous. 

16.  When  any  part  of  a  piece  of  glass  or  other  elec¬ 
tric  is  presented  to  a  body  electrified  positively  or  nega¬ 
tively,  that  part  becomes  possessed  of  the  contrary  elec¬ 
tricity  to  the  side  of  the  body  it  is  presented  to ;  and  the 
other  side  of  the  glass  is  possessed  of  the  same  kind  of 
electricity  as  the  other  hocly. 

17.  The  electricity  communicated  to  glass  and  other 
perfect  electrics,  does  not  spread,  but  is  confined  to  the 
part  where  it  is  communicated,  on  account  of  the  non¬ 
conducting  quality  of  the  glass. 

18.  To  effect  the  communication,  and  to  enable  it  to 
be  applied  to  the  whole  surface,  the  glass  is  covered  on 
both  sides  with  tin-foil,  or  some  other  conductor,  in  which 
case  the  glass  is  said  to  be  coated. 

19.  If  a  communication  by  means  of  a  conductor,  be 
made  between  the  two  sides  of  a  glass  thus  coated  and 
charged  with  electricity,  a  discharge  takes  place,  by 
which  the  two  sides  recover  their  natural  state. 

20.  The  coated  glass  may  either  be  flat  or  any  other 
form ;  but  cylindrical  jars  are  found  to  be  the  most  con¬ 
venient  form.  The  Leyden  phial  is  nothing  more  than 
a  glass  of  this  description. 


260 


ELECTRICITY. 


21.  When  several  jars  or  phials  are  connected  together 
so  as  to  be  charged  and  discharged  simultaneously,  they 
constitute  an  electrical  battery. 

22.  Electricity  is  capable  of  producing  the  most  power¬ 
ful  effects,  melting  the  metals,  and  tiring  all  the  inflam¬ 
mable  substances.  A  strong  shock  sent  through  metallic 
oxides,  frequently  reduces  them  to  a  metallic  state. 

23.  The  machines  by  which  electricity  is  artificially 
accumulated,  for  the  purpose  of  charging  jars  or  bat¬ 
teries,  are  constructed  with  either  a  cylinder  or  plate  ot 
glass,  which  is  whirled  round  in  contact  with  a  body 
called  a  rubber,  and  the  electricity  is  taken  off  as  it  is 
produced,  by  a  non-electric  called  the  prune  conductor. 

24.  Cylinder  machines  are  the  most  easily  constructed  ; 
but  plate  machines  are  the  most  compact  and  elegant. 

25.  Several  bodies  become  transparent  during  the  pas¬ 
sage  of  electricity  through  them  ;  a  circumstance  which 
has  given  rise  to  the  conjecture  that  electricity  may  be 
the  cause  of  all  transparency. 

20.  Metallic  points  attract  the  electricity  from  bodies, 
and  discharge  them  silently.  This  property  has  ren¬ 
dered  them  useful  in  defending  from  lightning. 

27.  When  electricity  enters  a  point,  it  appears  in  the 
form  of  a  star ;  when  it  issues  from  a  point,  it  puts  on 
the  appearance  of  a  brush  or  pencil. 

28.  Machines  may  be  put  in  motion  by  the  electric 
fluid  which  issues  from  a  point. 

29.  The  shock  of  an  electric  battery  will  communicate 
magnetism  to  steel  bars  lying  in  or  near  the  magnetic 
meridian;  and  a  magnetic  bar  may  have  its  poles  re¬ 
versed,  or  its  magnetic  properties  destroyed,  by  impart¬ 
ing  the  shock  while  it  is  in  different  positions. 

30.  Electricity  is  evolved  in  heating  and  cooling  of 
various  bodies;  also  in  the  evaporation  and  condensation 
of  vapours. 

31.  Vapour  requires,  for  its  natural  share,  a  greater 
quantity  of  electricity  than  water,  from  which  it  was 
produced. 

32.  When  a  quantity  of  vapour  is,  in  any  degree,  con- 


GALVANISM. 


2G1 


densed,  it  has,  therefore,  electricity  to  give  out ;  that  is, 
m  the  positive  state.  When  a  quantity  of  vapour  is  fur¬ 
ther  expanded,  it  requires,  for  its  natural  share,  more 
electricity  than  before ;  that  is,  in  the  negative  state. 

33.  By  the  ascent  of  vapour,  immense  quantities  of 
electricity  are  carried  from  its  reservoir,  the  earth ;  and, 
by  the  unceasing  alternations  of  rarefaction  and  conden¬ 
sation,  the  atmosphere  is  always  more  or  less  in  an  elec¬ 
trical  state. 

34.  Lightning  is  a  vast  accumulation  of  electricity. 

35.  Thunder  is  the  noise  produced  by  the  solid  parti¬ 
cles  of  air  rushing  together,  after  having  been  separated 
by  lightning  ;  the  rapidity  of  the  motion  of  which  is  such 
as  to  produce  a  vacuum  as  it  proceeds. 

30.  In  the  eruptions  from  volcanoes,  lightning  is  almost 
always  present ;  and  earthquakes  are  generally  accom¬ 
panied  by  a  disordered  state  of  the  atmosphere ;  often 
with  great  thunder-storms.  Hence,  electricity  is  sup¬ 
posed  to  be  intimately  connected  with  these  phenomena. 

37.  In  the  healing  art,  electricity  appears  capable  of 
producing,  in  manv  cases,  the  most  excellent  effects.  In 
applying  it,  the  general  rule  is  to  begin  gently,  and  to 
continue  the  application,  at  periodical  intervals,  for  a 
considerable  time. 


GALVANISM. 

Galvanism  is  a  species  of  electricity  which  is  produced 
by  a  peculiar  action  of  metallic  and  other  electrical  con¬ 
ductors  on  each  other. 

Abstract  of  Galvanism. 

1.  Galvanism  appears  only  to  be  a  method  of  exciting 
electricity.  The  first  efficient  observation  of  its  effects 
originated  with  Galvani,  from  whom  it  derives  its  name ; 
but  it  was  Volta  who  first  rendered  it  interesting,  by  dis¬ 
covering  the  method  of  accumulating  it. 

2.  Galvanic  electricity  is  produced  by  the  chemical 


262 


MAGNETISM. 


action  of  bodies  upon  each  other;  particularly  by  the 
oxidation  of  metals,  during  which  process,  considerable 
quantities  are  evolved. 

3.  It  appears  to  be  in  a  state  of  less  intensity  or  con¬ 
densation  than  the  electricity  obtained  by  the  electrical 
machine. 

4.  It  will  oxidize  metals,  and  set  fire  to  all  inflammable 
substances  :  it  wall  also  give  a  charge  to  a  Leyden  phial.  * 

5.  Of  all  known  substances,  the  nerves  of  animals,  re¬ 
cently  dead,  appear  to  be  the  most  easily  affected  by  it; 
and  constitute  electrometers  of  exquisite  delicacy. 

6.  It  is  conducted,  and  refused  a  passage  by  some 
substances,  as  common  electricity. 

7.  When  a  living  animal  forms  a  part  of  its  circuit,  it 
produces  a  sensation  resembling  that  of  the  electric 
shock. 

8.  Electricity  is  generated  by  the  galvanic  battery  ; 
but  only  collected  or  transferred  by  the  electrical  ma¬ 
chine  ;  and,  therefore,  the  effects  of  the  former  are  in¬ 
creased  by  insulation. 

9.  The  power  of  galvanism  in  consuming  wires,  is 
greatest  when  the  plates  are  numerous;  but  in  giving  a 
shock,  it  is  greatest  when  the  plates  are  large,  the  quan¬ 
tity  of  surface  in  each  case  being  the  same. 


MAGNETISM. 

A  peculiar  species  of  attraction,  excited  by  bodies 
called  magnets  or  loadstones,  receives  the  appellation  of 
magnetism. 

Abstract  of  Magnetism. 

1.  That  principle  which  produces  the  phenomena  of 
magnetism,  is  not  cognizable  by  our  senses,  except  by 
its  etlects ;  but  it  is  considered  to  be  a  lluid,  and  spoken 
of  under  the  denomination  of  the  magnetic  fluid. 

-2.  Iron  has  been  usually  considered  as  the  only  sub¬ 
stance  susceptible  of  magnetism  ;  but  late  investig'ations, 


MAGNETISM. 


263 

which  have  been  made  with  great  care,  have  rendered 
it  extremely  probable  that  both  nickel  and  cobalt  like¬ 
wise  submit  to  the  influence  of  the  same  power. 

3.  Magnets  are  either  natural  or  artificial ;  natural 
magnets  are  ores  of  iron,  dug  out  of  the  earth  in  a  mag- 
netical  state ;  artificial  magnets  are  made  of  steel,  by 
the  help  of  a  natural  magnet. 

4.  In  every  magnet  there  are  two  opposite  points, 
which  at  all  times  and  places,  will,  if  the  magnet  be  at 
liberty  to  move  either  without  or  with  very  little  friction, 
turn  to  the  poles  of  the  world,  or  nearly  so. 

5.  It  is  this  singular  property,  which  is  called  polarity, 
that  renders  the  magnet  so  useful  in  navigation. 

6.  The  poles  of  magnets,  if  of  the  same  name,  as 
when  two  north  or  two  south  poles  are  brought  near 
together,  repel  each  other;  different  poles,  on  the  con¬ 
trary,  attract  each  other.  The  centre  of  a  magnet 
neither  attracts  nor  repels. 

7.  The  earth  itself  acts  as  a  great  magnet,  the  poles 
of  which  nearly  but  not  quite  coincide  with  the  geo¬ 
graphical  poles. 

8.  It  is  this  difference  between  the  magnetical  and  the 
geographical  poles,  that  produces  the  declination  of  the 
needle,  which  turns  to  the  former,  and  only  indicates  the 
latter  by  the  nearness  of  the  two. 

9.  The  magnetical  poles  are  not  fixed  points,  but  the 
cause  of  their  motion  is  unknown. 

10.  The  constant  change  which  the  motion  of  the 
magnetic  poles  produces  in  the  declination  of  the  needle , 
is  the  cause  of  what  is  called  the  variation  of  the  com¬ 
pass. 

11.  At  all  places  not  90  degrees  from  the  magnetic 
poles,  one  pole  of  a  magnet  suspended  by  its  centre  sinks 
below  the  horizon,  which  is  called  the  dip  or  inclination 
of  the  needle. 

12.  In  the  northern  hemisphere,  it  is  the  north  pole 
which  dips,  and  in  the  southern  hemisphere  it  is  the 
south  pole. 

13.  To  render  a  natural  magnet  capable  of  lifting  a 


264 


PNEUMATICS. 


weight  with  the  force  of  both  poles,  it  is  furnished  with 
an  armature  ;  an  artificial  magnet,  for  the  same  purpose 
is  made  in  the  form  of  a  horse-shoe. 

14.  Soft  iron  receives  magnetism  with  great  facility, 
but  loses  it  almost  immediately :  steel  on  the  contrary, 
hut  especially  hardened  steel,  is  not  easily  affected  ;  but 
the  portion  it  receives,  it  permanently  retains. 

15.  A  magnet  employed  in  the  communication  of 
magnetism,  rather  gains  than  loses  strength. 

10.  A  steel  bar,  rendered  magnetic,  and  resting  by  its 
centre  upon  a  point,  so  as  to  be  at  liberty  to  turn  in  any 
direction,  is,  with  the  box  which  contains  it,  and  a  card 
on  which  are  written  the  names  of  the  winds,  called  the 
mariner’s  compass. 

17.  The  azimuth  compass  differs  chiefly  from  the 
above  in  having  tvyo  sights,  through  which  may  be  seen 
the  sun  or  any  heavenly  body,  of  which  the  azimuth  is 
to  be  taken. 

18.  The  dipping  needle  is  made  by  accurately  sus¬ 
pending  a  bar  of  steel,  in  an  unmagnetical  state,  on  the 
pivots  of  an  axis  passing  through  its  centre  ;  it  is  then 
magnetized,  and  dips  according  to  the  action  of  the  north 
or  south  pole  upon  it. 

PNEUMATICS. 

The  science  of  Pneumatics  treats  of  the  density,  pres¬ 
sure,  and  elasticity7-  of  the  air,  and  the  effects  which  they 
produce. 

Pneumatics,  being  a  science  somewhat  remote  from 
the  present  design  of  this  work ;  and  having  the  proper¬ 
ties  of  the  air,  under  the  head  of  chemistry ;  we  shall, 
therefore,  let  an  abstract  of  this  science  suffice. 

Abstract  of  Pneumatics. 

1.  The  air  is  the  fluid  which  we  breathe;  with  the 
vapours  it  contains,  it  is  called  the  atmosphere. 

2.  The  particles  of  air  are  solid  and  impermeable,  like 
those  of  the  hardest  bodies. 


PNEUMATICS. 


265 

3.  The  air  is  invisible,  because  of  its  great  trans¬ 
parency ;  when  unconfined  it  is  imperceptible  to  the 
touch,  because  its  particles  move  among  each  other  with 
a  facility  so  great  that  we  perceive  no  force  to  be 
required  in  displacing  it ;  we  move  in  it  as  if  we  had  no 
pressure  upon  us,  because  its  pressure  is  in  every  direc¬ 
tion  the  same. 

4.  The  weight  of  air  is  to  that  of  water,  as  832  to  1. 

5.  i  he  air  expands  in  proportion  to  the  diminution  of 
the  pressure  upon  it;  it,  therefore,  becomes  rare  as  we 
ascend  in  the  atmosphere :  at  the  height  of  3i  miles,  a 
given  bulk  of  it  takes  up  twice  the  space  it  would  do  at 
the  surface  of  the  earth. 

6.  The  air-pump  is  a  machine  for  exhausting  the  air 
out  of  vessels  ;  but  the  best  air-pumps  have  not  so  com¬ 
pletely  attained  their  object  as  to  produce  an  absolute 
vacuum,  or  place  void  of  air. 

7.  The  rising  of  water  in  common  pumps,  is  owing  to 
the  pressure  of  the  atmosphere  being  removed  from  one 
pait  of  the  fluid,  which,  therefore,  yields  at  that  part  by 
the  pressure  on  the  other  parts,  till  the  column  of  water 
sustained  is  equal  to  the  column  of  air  sustaining  it. 

8.  Suction,  unless  so  applied  as  to  mean  the  pressure 
of  the  atmosphere,  is  a  non-entity,  and  incapable  of  pro¬ 
ducing  effects. 

9.  1  he  pressure  of  the  atmosphere,  which  is  in  gen¬ 
eral  15  lbs.  on  every  square  inch,  is  not  invariably  the 
same,  but  is  in  a  middle-sized  person  1800  pounds  less  at 
one  time  than  another;  and  when  the  pressure  is  greatest, 
we  feel  exhilarated  rather  than  depressed. 

10.  On  the  variable  pressure  of  the  atmosphere,  and 
the  changes  thereby  occasioned,  is  founded  the  utility 
of  the  barometer,  by  which  instrument  the  pressure  is 
measured. 

11.  I  he  best  barometer  is  the  common  one,  with  a 
straight  tube,  and  short  scale  of  variation;  other  kinds, 
in  contriving  which,  the  extension  of  the  scale  of  variation 
has  been  chiefly  aimed  at,  are  all  more  or  less  defective. 

12.  In  observations  for  measuring  the  height  of  moun- 
23 


PNEUMATICS. 


266 

tains,  a  thermometer  must  be  used  along  with  the 
barometer,  in  order  that  the  due  allowance  may  be 
made  for  the  elFects  of  temperature  in  lengthening  or 
shortening  the  column  of  mercury  ;  and  the  surface  of 
the  mercury  in  the  cistern  must  be  at  a  fixed  distance 
from  the  scale,  before  the  height  of  the  mercury  is 
read  olf! 

13.  The  air  may  be  condensed,  or  forced  into  less 
compass  than  it  occupies  at  the  surface  of  the  earth,  by 
means  of  a  contrivance  called  a  condensing  engine. 

14.  When  much  condensed,  the  efforts  of  the  air  to 
expand  are  so  great,  that  it  may  be  employed  as  a 
powerful  motive  force.  On  this  depend  the  properties 
of  air-guns. 

15.  An  hygrometer  is  an  instrument  for  measuring  the 
dryness  or  moisture  of  the  atmosphere. 

16.  De  Saussure’s  hygrometer  is  made  of  clarified  hair; 
De  Luc’s,  of  a  slip  of  Whalebone  cut  across  the  grain. 

17.  The  depth  of  rain  which  falls  on  the  earth  is  esti¬ 
mated  by  the  quantity  which  falls  within  a  small  vessel 
called  a  rain-gauge. 

18.  The  strength  of  wind  is  measured  by  its  power  to 
support  bodies  out  of  the  position  of  equilibrium. 

19.  The  winds  are  the  consequences  of  variations  con¬ 
stantly  taking  place  in  the  density  of  the  atmosphere, 
principally  by  the  action  of  solar  heat. 

20.  Variable  winds  are  supposed  to  be  the  chief 
causes  of  the  rising  and  falling  of  the  barometer,  which, 
in  countries  not  subject  to  them,  remains  almost  uniformly 
at  the  same  height. 

21  In  deriving  from  the  barometer,  prognostics  of  the 
weatner,  the  tendency  of  the  mercury  to  an  upward  or 
downward  motion,  rather  than  its  absolute  height  at  any 
time,  is  chiefly  to  be  regarded. 

22.  When  the  air  reaches  the  ear  in  a  state  of  vibra* 
tory  motion,  it  occasions  the  sensations  of  sound. 

23.  Bodies  which  produce  the  clearest  and  strongest 
sound,  are  in  general  the  most  elastic. 

24.  The  quality  of  sound,  in  point  of  tone,  is  determi- 


OPTICS. 


267 

ned  by  the  greater  or  smaller  number  of  vibrations  made 
by  the  sounding  body  in  a  given  time. 

Sonorous  bodies,  when  sufficiently  near,  cause 
each  other  to  sound,  although  but  one  of  them  is  struck, 
provided  they  be  in  unison,  or  disposed  to  make  vibra¬ 
tions  equally  frequent. 

26.  An  echo  is  the  reflection  of  a  sound,  and  cannot 
be  heard  unless  the  original  sound  has  traversed  the 
distance  of  about  110  feet. 

27.  Speaking  and  hearing  trumpets  act  upon  the 
principle  of  reflecting  towards  their  axes,  and  thereby 
concentrating  the  sound  transmitted  through  them. 


OPTICS. 

This  is  a  branch  of  Natural  Philosophy  which  treats 
ot  the  mechanical  properties  of  light,  and  the  phenomena 


Abstract  of  Optics. 

1.  The  particles  of  light,  which  are  inconceivably 
small,  proceed  from  luminous  bodies  in  right  lines.  J 

2.  Consequently  the  density  of  light  is  inversely  as  the 
square  of  the  distance  from  the  luminous  centre. 

3.  Light  moves  at  the  rate  of  nearly  200,000  miles  in 
one  second  of  time. 

4.  Its  impression  on  the  retina  is  not  instantaneous: 
hence  though  its  particles  may  be  separately  projected 
so  as  to  be,  in  their  progress,  at  the  rate  of  1000  miles 
apart  its  velocity  is  sufficient  to  produce  a  distinct  vision, 

.  i7ver3r  ray  carries  with  it  the  image  of  the 

point  from  which  it  was  emitted;  when,  therefore,  pen- 
cils  of  rays  from  every  point  of  an  object  are  united  in 
the  same  order  in  which  they  were  emitted,  they  form 
an  image  or  representation  of  that  object,  at  the  place 
where  they  are  thus  emitted.  1 

6.  All  the  rays  of  light,  which  enter  another  medium 
obliquely,  suflTer  refraction;  that  is,  they  either  move 
farther  from,  or  nearer  to,  the  perpendicular,  as  the 


OPTICS. 


2(58 

medium  into  which  they  enter  is  rare  or  denser  than 
the  other  medium. 

7.  On  the  refrangibility  of  light  depends  the  proper- 
tics  of  lenses* 

8.  Convex  lenses  collect  the  rays  of  light,  and  make 
them  converge  to  a  centre  or  focus. 

9.  Concave  lenses  disperse  the  rays  of  light,  the  power 
of  refraction  not  being  towards  the  centre,  but  towards 
their  circumference. 

10.  When  light  strikes  upon  a  surface,  it  is  reflected 
so  that  the  angle  of  reflection  is  equal  to  the  angle  ot 
incidence ;  on  this  the  properties  of  mirrors  depend. 

11.  Plane  mirrors  have  no  other  effect  than  that  of 
changing  the  direction  of  the  incident  rays. 

12.  Convex  mirrors  cause  parallel  rays  to  diverge. 

19.  Concave  mirrors  collect  parallel  rays,  or  cause 

them  to  converge  to  a  focus. 

14.  Mixed  mirrors  exhibit  distorted  images,  because 
they  increase  or  lessen  the  divergence  or  convergence  ot 
the  rays  in  one  or  two  directions  only. 

15.  "The  solar  beam  is  composed  of  rays  possessed  of 
different  degrees  of  refrangibility,  and  these  differences 
of  refrangibility,  which  arc  dependent  on.  the  size  of 
their  particles, ’produce  all  the  phenomena  of  colours. 

16.  The  solar  beam,  or  white  light,  contains  rays  of 
seven  ditferent  colours,  viz.  red,  orange,  yellow,  green, 
blue,  indigo,  and  violet.  These  are  called  the  primitive 
colours,  because  they  are  immutable,  except  by  inter¬ 
mixture. 

17.  It  is  inferred  that  red  light  is  composed  of  par¬ 
ticles  of  the  largest  size,  because  it  is  found  to  be 
capable  of  struggling  through  thick  and  resisting  mediums, 
which  stop  every  other  colour. 

18.  The  size  of  the  particles  of  other  colours  is  in 
the  order  of  their  enumeration,  the  violet  being  the 

smallest.  .. 

It).  The  rainbow  is  owing  to  the  separation  of  the 
light  into  its  primitive  colours,  by*  the  drops  of  falling 
rain,  which  act  like  a  prism. 


OPTICS. 


269 


20.  The  rays  of  light  are  inflected  when  they  pass 
very  near  a  body,  and  deflected  when  they  pass  at  a 
greater  distance. 

21.  Those  rays  which  deviate  the  least  by  refraction, 
deviate  the  most  by  flection. 

22.  The  images  of  all  visible  objects  are  depicted  cn 
the  retina,  in  an  inverted  position.. 

23.  With  two  eyes,  vision  is  not  only  more  distinct 
but  more  accurate  than  with  one. 

24.  A  good  eye  can  see  most  distinctly  when  the  rays 
fall  exactly  on  the  retina. 

25.  The  best  eye  can  hardly  distinguish  any  object 
that  subtends  an  angle  of  less  than  half  a  minute. 

26.  The  apparent  magnitude  of  objects  is  dependent, 
on  the  angle  under  which  they  are  seen,  or  the  size  of 
their  images  depicted  on  the  retina. 

'  27.  The  long-sighted  require  convex  spectacles,  the 

short-sighted,  concave  ones. 

28.  Burning  lenses  must  be  convex,  and  burning  mir¬ 
rors  concave,  as  the  effects  of  both  these  instruments 
are  dependent  on  the  condensation  of  the  incident  light. 

29.  Microscopes  are  optical  instruments  for  viewing 
small  objects.  They  appear  to  magnify  objects,  because 
they  enable  us  to  see  them  with  distinctness,  nearer  than 
the  natural  limits  of  vision. 

30.  Refracting  telescopes  are  formed  by  lenses  only ; 
when  manufactured  in  the  best  manner,  they  are  either 
furnished  with  an  acromatic  object-glass,  which  corrects 
the  defect  arising  from  the  unequal  refraction  of  the 
different  rays,  by  a  combination  of  one  or  two  convex 
lenses  with  a  concave  one  of  a  different  sort  of  glass;  or, 
though  more  rarely,  they  have  an  aplanatic  object- 
glass,  which  corrects  the  same  defect  by  a  combination 
of  a  plano-convex  and  meniscus  glass,  with  a  fluid  be¬ 
tween  them  that  acts  like  a  third  lens. 

31.  Reflecting  telescopes  consist  of  lenses  and  at  least 
of  one  speculum.  When  I  here  is  more  than  one  specu¬ 
lum,  the  second  is  6nly  about  one-fourth  of  the  size  of 
the  other,  and  may  be  either  convex,  concave,  or  plane. 

23* 


ASTRONOMY. 


270 

32.  Reflecting  telescopes  admit  of  a  much  greater 
magnifying  power  in  a  given  length,  than  refracting 

telescopes. 

33.  The  binocular  telescope  consists  of  two  telescopes 
so  combined,’  that  both  eyes  may  be  employed  in  looking 
at  the  same  object. 


A  STRONG M Y 

is  the  science  which  treats  of  the  motions,  eclipses, 
magnitudes,  periods,  and  other  phenomena  of  the  heaven¬ 
ly  bodies. 

Abstract  of  Astronomy. 

1.  The  solar  system  comprises  the  sun  and  all  the 
bodies  that  revolve  around  him,  viz  :  the  comets,  the 
planets  with  their  respective  satellites,  and  the  asteroids. 

2.  The  number  of  the  comets  is  unknown  ;  that  of 
the  planets,  so  far  as  yet  discovered,  is  seven  ;  the  satel¬ 
lites  eighteen ;  and  the  asteroids  four. 

3.  The  figure  of  the  earth  is  not  that  of  a  perfect 
globe,  but  an  oblate  spheroid,  flattened  a  little  at  the 
poles,  by  its  revolution  on  its  axis. 

4.  The  planets  Jupiter  and  Saturn  are  also  observed 
to  be  flattened  at  the  poles  like  the  earth,  but  in  a  great¬ 
er  degree,  evidently  because  their  diurnal  revolution  is 
swifter. 

'5.  The  orbits  of  all  the  planets,  asteroids,  and  comets, 
are  ellipses,  having  the  sun  in  one  of  their  foci;  but  the 
orbits  of  the  two  former  classes  of  bodies  are  nearly 
circular,  while  the  orbits  of  the  comets  are  all  very 
eccentric. 

0.  The  orbits  of  the  satellites  are  also  ellipses,  in  one 
of  the  foci  of  which  is  sustained  the  primary  planet 
round  which  they  move. 

7.  The  periods,  distances,  and  magnitude  of  the  planets, 
have  all  been  determined  with  very  considerable  exact¬ 
ness;  the  same  circumstances  respecting  the  asteroids. 


ASTRONOMY. 


271 


are  also  evidently  determinable,  though  the  results  yet 
laid  down,  have  not,  from  the  recent  date  of  their  dis¬ 
covery,  been  so  amply  confirmed,  as  to  be  fully  relied  on; 
but  the  comets  recede  to  such  immense  distances,  and 
there  is  so  much  uncertainty  in' identifying  them,  that 
their  elements  are  hypothetical. 

8.  The  planets,  comets,  and  asteroids,  are  preserved 
in  their  orbits,  by  the  joint  effects  of  the  power  of  attrac¬ 
tion,  which  acts  in  a  right  line  from  them  to  the  sun,  and 
a  projectile  or  centrifugal  force,  which  would  carry  them 
off  in  a  tangent  to  the  curve  of  revolution. 

9.  The  powers  which  preserve  the  satellites  in  their 
orbits,  are  the  same  as  those  that  act  upon  the  planets 
and  comets,  but  the  centripetal  force  is  exercised  by  the 
primary. 

10.  The  body  of  the  sun  is  supposed  to  be  opaque, 
ard  to  be  surrounded  with  a  double  set  of  clouds,  the 
upper  stratum  of  which  forms  the  luminous  globe  we 
behold. 

11.  The  planets  revolve  round  an  imaginary  line  or 
axis  within  themselves,  and  the  time  in  which  they  per¬ 
form  this  rotation,  constitutes  their  day  and  night. 

12.  The  time  in  which  a  planet  revolves  round  the 
sun,  forms  its  year. 

13.  The  diversity  of  seasons  is  occasioned  by  the  incli¬ 
nation  of  the  axes  of  a  planet  to  the  plane  of  its  orbit. 

14.  The  annual  and  diurnal  revolutions  of  the  planets 
are  all  performed  from  west  to  east. 

15.  The  satellites,  also,  revolve  from  west  to  east,  with 
the  exception  of  the  ‘■atellites  of  Herschel,  which  appear 
to  move  in  a  contrary  direction. 

1(5.  The  fixed  stars  are  distinguished  from  the  bodies 
i>f  the  solar  system,  by  the  twinkling  light  they  afford, 
dy  their  having  no  parallax,  and  by  their  having,  even 
through  the  best  telescopes,  no  sensible  magnitude. 

17.  The  naked  eye  cannot  behold  above  five  hundred 
tars  in  the  whole  hemisphere;  but  the  number  dis¬ 
covered  with  the  assistance  of  a  telescope  exceeds  all 
calculation. 


272 


ASTRONOMY. 


18.  Every  fixed  star  is  supposed  to  be  a  sun,  shining 
by  its  own  light,  and  surrounded  by  planetary  worlds 
like  those  of  the  solar  system. 

19.  The  tides  are  an  effect  of  the  attraction  of  the 
sun  and  moon  upon  the  ocean.  When  these  luminaries 
act  together,  or  in  the  same  line,  they  occasion  spring 
tides ;  when  they  counteract  each  other’s  attraction, 
neap  tides  take  place. 

20.  Eclipses  of  the  moon  are  owing  to  the  shadow  of 
the  earth  falling  upon  the  moon. 

21.  Eclipses  of  the  sun  occur,  when  the  moon  coming 
between  the  earth  and  the  sun,  throws  a  shadow  on  the 
earth. 

22.  Motion  is  the  measure  of  time,  and  the  motions  of 
the  heavenly  bodies  are  the  basis  by  which  all  other 
motions  are  measured. 

23.  The  day  is  a  natural  division  of  time,  that  is,  it 
comprises  a  portion  of  time  measured  out  by  the  com¬ 
pletion  of  certain  phenomena,  successive  according  to 
regular  laws. 

The  periodical  and  synodical  lunar  months  are  also 
natural  divisions  of  time,  but  no  other ;  the  year,  and 
lunar  and  solar  cycles,  are  of  the  same  character  as  the 
lunar  months ;  the  cycle  of  indiction,  and  the  olympiad 
are  examples  of  the  artificial  division  of  time. 

Thirty  days  hath  September, 

April,  June,  and  November; 

All  the  rest  have  thirty-one, 

Except  the  leap-year:  that’s  the  time, 

When  February’s  days  are  twenty  and  nine. 


MECHANICAL  EXERCISES. 


OF  IRON. 

Of  all  metallic  substances,  iron  is  the  most  abundantly 
diffused,  and  the  most  intrinsically  valuable. 

(This  metal  is  described  under  the  head  of  Chemistry.) 

Iron  is  employed  in  three  states,  viz:  that  of  cast  iron, 
wrought  iron,  and  steel.  Cast  iron  is  the  metal  in  its 
first  state,  rendered  fusible  by  its  combination  with  those 
two  substances  which  chemists  distinguish  by  the  names 
carbon  and  oxygen.  In  the  great  iron  works,  the  ore, 
broken  in  small  pieces,  and  mixed  with  a  portion  of 
limestone  to  promote  its  fusion,  is  thrown  into  a  furnace, 
which  is  from  1G  to  30  feet  high.  Baskets  of  charcoal 
or  coke,  in  due  proportion,  are  thrown  in  along  with  it. 
A  part  of  the  bottom  of  the  furnace  is  filled  with  fire 
only.  This  being  kindled,  the  whole  is  roused,  by  the 
blast  of  the  great  bellows,  to  a  most  intense  heat.  The 
metal,  as  it  is  reduced,  sinks  down  through  the  fuel,  and 
collects  at  the  bottom  of  the  furnace.  More  ore  and 
fuel  are  supplied  above,  and  the  operation  goes  on,  till 
the  melted  metal,  increasing  in  quantity,  rises  almost  to 
the  aperture  of  the  blast ;  a  passage  is  then  made  for  it 
at  the  side  of  the  furnace,  and  it  is  run  into  what  is 
called  pigs  of  cast  iron.  A  furnace  will  furnish  daily 
irom  two  to  five  tons  of  iron,  according  to  the  richness  of 
the  ore,  and  the  skill  with  which  the  operation  is  con¬ 
ducted.  Ores  of  iron  are  combined  with  magnesia,  are 
very  refractory,  and,  as  well  as  those  which  contain  sul¬ 
phur  and  arsenic,  require  to  be  roasted  before  they  are 
cast  into  the  smelting  furnace. 

Pig-iron  is  of  very  different  qualities;  that  which  is 
called  No.  1,  arid  the  fracture  of  which  is  of  a  dark 
colour,  runs  so  fluid  as  to  be  admirably  suited  for  grates, 
tmd  ornamental  work.  Cast-iron  cutlery  is  manufactured 

*S  W 


274 


MECHANICAL  EXERCISES. 


from  t,  as  no  other  would  run  fine  enough  for  the  pur¬ 
poses  to  which  it  is  applied,  such  as  forks  and  small 
scissors,  fish-hooks  and  needles.  These  articles  obtain, 
by  anealing,  a  considerable  degree  of  malleability, 
and  are  even  capable  of  being  welded.  When  great 
strength  is  required,  as  for  large  wheels,  beams,  pillars, 
or  rail-ways,  the  iron  which  contains  a  smaller  propor¬ 
tion  of  carbon  is  preferable ;  as  that  called  No.  2.  The 
proportion  of  carbon  in  cast  iron  varies,  in  the  different 
sorts,  from  one-fifteenth  to  one  twenty-fifth.  Cast  iron 
also  frequently  contains  a  portion  of  the  phosphuret  of 
iron ;  in  which  case,  it  breaks  of  a  white  colour,  and 
must,  from  its  excessive  hardness,  be  rejected  for  pur¬ 
poses  which  require  it  to  be  filed,  or  turned,  or  cut  with 
the  chisel.  It  may  be  observed,  that  the  whiter  the 
metal  is,  the  harder  it  is,  also;  whether  these  properties 
are  owing  to  its  quality,  or  the  mode  of  its  management. 

Crude  or  cast  iron  is  converted  into  wrought  iron,  by 
keeping  it  in  a  state  of  fusion  for  a  considerable  time, 
and  repeatedly  stirring  it  in  the  furnace;  the  oxygen 
•  and  carbon  which  it  contains,  unite,  and  fly  off  in  a  state 
of  carbonic  acid  gas,  and  as  this  takes  place  the  iron 
becomes  more  infusible  ;  it  gets  thick  or  stiff  in  the  fur¬ 
nace;  and  the  workmen  know,  bv  this  appearance,  that 
it  is  time  to  submit  it  to  the  repeated  action  of  the  ham¬ 
mer,  or  the  regular  pressure  of  large  steel  rollers,  by 
which  the  parts  which  still  partake  of  the  nature  of 
crude  iron  so  much  as  to  retain  the  fluid  state,  are  forced 
out,  and  the  metal  is  rendered  malleable,  ductile,  more 
closely  compacted,  of  a  fibrous  texture,  and  totally 
infusible.  In  this  state  it  is  known  in  commerce  'by  the 
name  of  bar  iron.  The  loss  of  weight  sustained  by  iron, 
in  the  process  of  refining,  is  considerable,  generally 
amounting  to  one-fourth,  and  sometimes  to  one-half. 

Forged,  like  cast  iron,  varies  greatly  in  its  quality. 
1  bus  some  of  it  is  tough  and  malleable  when  it  is  hot 
and  when  it  is  cold.  This  is  the  iron  in  common  use, 
und  it  is  the  best,  and  most  useful.  It  may  be  known 
generally  by  the  equable  surface  of  the  forged  bar,  which 


MECHANICAL  EXERCISES. 


275 


is  free  from  transverse  fissures,  or  cracks  in  the  edges, 
and  by  a  clear  white,  small  grained,  or  rather  fihroui 
texture.  The  best  and  toughest  iron  is  that  which  has 
the  most  fibrous  texture,  and  is  of  a  clear  greyish  colour. 
This  fibrous  appearance  is  given  by  the  resistance  which 
its  particles  make  to  separation.  The  texture  of  the 
next  best  iron,  which  is  also  malleable  in  all  tempera' 
lures,  consists  of  clear  whitish  small  grains,  intermixed 
with  fibres.  Another  kind  is  tough  when  it  is  heated, 
but  brittle  when  cold.  This  is  called  cold-short-iron,  and 
is  distinguished  by  a  texture  consisting  of  large  shining 
plates,  without  any  fibres.  It  is  less  liable  to  rust  than 
any  other  description  of  forged  iron.  A  fourth  kind  of 
iron  called  hot-short,  is  extremely  brittle  when  hot,  and 
malleable  when  cold.  On  the  surface  and  edges  of  the 
bars  of  this  kind  of  iron,  transverse  cracks  or  fissures 
may  be  seen,  and  its  internal  colour  is  dull  and  dark. 

The  quality  of  iron  may  be  much  improved  by  violent 
compression,  as  by  forging  and  rolling,  especially  when  it 
is  not  long  exposed  to  violent  heat,  which  injures  and  at 
length  destroys  its  metallic  properties.  But  though  iron 
is  rendered  malleable  by  hammering,  this  operation  may 
be  continued  so  long  as  to  deprive  it  of  its  malleability. 

Steel  is  made  of  the  purest  malleable  iron,  by  a  pro¬ 
cess  called  cementation.  In  this  operation,  layers  of  bars 
of  malleable  iron,  and  layers  of  charcoal,  are  placed  one 
upon  another,  in  a  proper  furnace,  the  air  is  excluded, 
the  fire  raised  to  a  considerable  degree  of  intensity,  and 
kept  up  for  8  or  10  days.  If,  upon  the  trial  of  a  bar, 
the  whole  substance  is  converted  into  steel,  the  fire  is 
extinguished,  and  the  whole  is  left  to  cool  for  6  or  8  days 
longer.  Iron  thus  prepared  is  called  blistered  steel,  from 
the  blisters  which  appear  on  its  surface.  In  England, 
charcoal  alone  is  used  for  this  purpose ;  but  Duamel 
found  an  advantage  in  using  from  one- fourth  to  one-third 
of  w'ood-ashes,  especially  when  the  iron  was  not  of  so 
good  a  quality  as  to  afford  steel  possessing  tenacity  c  ' 
body  as  well  as  hardness.  These  ashes  prevent  the 
steel-making  process  from  being  effected  so  rapidly  as  it 


2TG 


MECHANICAL  EXERCISES. 


would  otherwise  be,  and  give  the  steel  pliability  without 
diminishing  its  hardness.  The  blisters  on  the  surface  of 
the  steel,  under  this  management,  are  smaller  and  more 
numerous.  He  also  found  that  if  the  bars,  when  they 
are  put  into  the  furnace,  be  sprinkled  with  sea  salt,  this 
ingredient  contributes  to  give  body  to  the  steel.  If  the 
cementation  be  continued  too  long,  the  steel  becomes 
porous,  brittle,  of  a  darker  fracture,  more  fusible,  and 
capable  of  being  welded.  On  the  contrary,  steel  cement 
ed  with  earthy  infusible  powders  is  gradually  reduced 
to  the  state  of  forged  iron  again.  Excessive  or  repeated 
heating  in  the  forge  is  attended  with  the  same  effect. 

The  properties  of  iron  are  remarkably  changed  by 
cementation,  and  it  acquires  a  small  addition  to  its 
weight,  which  consists  of  the  carbon  it  has  absorbed  from 
the  charcoal,  and  mounts  to  about  the  hundred-and- 
tiftieth,  or  two-hundreth  part.  It  is  much  more  brittle 
and  fusible  than  before;  and  it  may  still  be  welded  like 
bar-iron,  if  it  has  not  been  fused  or  over-cemented ;  but 
by  far  the  most  important  alteration  in  its  properties  is, 
that  it  can  be  hardened  or  softened  at  pleasure.  If  it 
be  made  red-hot,  and  instantly  cooled,  it  attains  a  degree 
of  hardness  which  is  sufficient  to  cut  almost  any  other 
substance ;  but,  if  heated  and  cooled  gradually,  it  be¬ 
comes  nearly  as  soft  as  pure  iron,  and  may,  with  much 
the  same  facility,  be  manufactured  into  any  determined 
form.  A  rod  of  good  steel,  in  its  hardest  state,  possesses 
so  little  tenacity,  that  it  may  be  broken  almost  as  easily 
as  a  rod  of  glass,  of  the  same  dimensions.  This  brittle¬ 
ness  can  only  be  diminished  by  diminishing  its  hardness; 
and  in  the  proper  management  of  this  point,  for  different 
purposes,  consists  the  art  of  tempering.  The  colours 
which  necessarily  appear  on  the  surface  of  the  steel 
slowly  heated,  are  yellowish-white,  yellow,  or  straw 
colour,  gold  colour,  brown,  purple,  violet,  and  deep  blue. 
These  signs  direct  the  artist  in  reducing  the  hardness  of 
steel  to  any  particular  standard.  If  steel  be  too  hard,  it 
will  not  be  proper  for  tools  which  are  intended  to  have 
a  fine  edge,  because  it  will  be  so  brittle,  that  the  edge 


MECHANICAL  EXERCISES. 


277 

will  soon  become  notched :  if,  on  the  contrary,  it  be  toe 
soft,  it  is  evident  that  the  edge  will  turn  or  bend.  Some 
artists  inclose  the  tools  to  be  hardened  in  an  iron  case  or 
box,  and  slowly  heat  them  to  ignition ;  they  then  take 
the  box  out  of  the  tire,  and  drop  the  pieces  into  water,  in 
such  a  manner  as  will  allow  them  to  come  as  little  as  pos¬ 
sible  into  contact  with  the  air.  This  method  answers  two 
good  purposes;  it  causes  the  heat  to  be  more  equally 
applied,  and  prevents  the  scaling  occasioned  by  the  con 
tact  of  air.  When  the  work  has  been  polished,  and 
well  defended  from  the  air,  it  is,  when  hardened,  nearly 
as  clear  as  before.  If  the  tool  be  unpolished,  they 
brighten  its  surface  upon  a  stone.  It  is  then  laid  upon 
burning  charcoal,  or  upon  the  surface  of  melted  lead,  or 
upon  an  ignited  bar  or  plate  of  iron,  till  it  appears  the 
desired  colour;  at  which  instant,  they  plunge  it  into  cold 
water.  1  he  yellowish-white  indicates  a  temper  so  little 
reduced  as  to  be  used  for  edge-tools;  the  yellow,  or  straw 
colour,  the  gold  colour,  and  the  brown,  are  used  for  pen¬ 
knives,  razors,  and  gravers ;  the  purple,  for  tools  used  in 
working  upon  metals,  especially  iron  ;  the  violet,  for 
springs,  and  for  instruments  for  cutting  soft  substances, 
such  as  cork,  leather,  and  the  like ;  but  if  the  last  blue 
be  waited  for,  the  hardness  of  the  steel  will  scarcely 
exceed  that  of  iron.  When  soft  steel  is  heated  to  any 
of  these  colours,  and  then  plunged  into  water,  it  does  not 
acquire  nearly  so  great  a  degree  of  hardness  as  if  pre¬ 
viously  made  quite  hard,  and  then  reduced  by  temper¬ 
ing.  The  degree  of  ignition  required  to  harden  steel  is 
ol  different  kinds.  I  he  best  kinds  require  only  a  low 
red  heat.  It  has  been  ingeniously  supposed,  that  the 
hardness  of  steel  depends  on  the  intimate  combination  of 
its  carbon;  and,  on  this  supposition,  it  follows,  that  the 
heat  which  effects  this  is  the  best,  and  that  a  higher  de¬ 
gree  will  be  injurious. 

The  texture  ot  steel  is  rendered  uniform  by  fusion, 
When  it  has  undergone  this  operation,  it  is  called  cast- 
steel;  which  is  wrought  with  more  difficulty  than  com¬ 
mon  steel,  because  it  is  more  fusible,  and  is  dispersed 
24 


MECHANICAL  EXERCISES. 


278 

under  the  hammer,  if  heated  to  a  white  heat.  The  cast 
steel  of  England  is  made  from  the  fragments  of  the 
crude  steel  of  the  manufactories  and  steel  works.  A 
crucible,  about  ten  inches  high  and  seven  inches  in  dia¬ 
meter,  is  filled  with  the  fragments,  and  placed  in  a 
wind  furnace,  like  that  of  the  foundries,  but  smaller, 
because  intended  to  contain  one  pot  only.  It  is,  like¬ 
wise,  furnished  with  a  cover  and  chimney,  to  increase 
he  draught  of  the  air.  The  furnace  is  entirely  filled 
with  coke,  and  five  hours  are  required  for  the  perfect 
fusion  of  the  steel.  It  is  then  cast  into  ingots,  and  after 
wards  forged  in  the  same  manner  as  other  steel,  but  with 
less  heat  and  more  precaution,  as  it  is  more  liable  to 
break.  Cast  steel  is  becoming  more  and  more  in  use, 
but  must  necessarily  be  excluded  from  many  works  of 
considerable  size,  on  account  of  the  ditficulty  of  welding 
it,  and  the  facility  with  which  it  is  degraded  in  the  fire. 
Cast  steel  takes  a  fine  firm  edge,  and  receiving  an 
exquisite  polish,  of  which  no  other  sort  of  steel  is,  in  so 
high  a  degree,  susceptible,  it  is  made  use  of  for  all  the 
finest  cutlery  in  England ;  it  is  too  imperfectly  fluid  to 
oe  cast  into  small  wires.  The  tenacity  of  steel  ham¬ 
mered  at  a  low  heat,  or  even  when  cold,  is  considerably 
increased ;  but  the  effect  of  the  hammering  is  taken  olf 
by  strong  ignition.  Tools,  therefore,  made  of  cast  steel, 
and  intended  to  sustain  a  good  edge,  for  cutting  iron  and 
other  metals,  are  not  afterwards  softened,  but  the  ignition 
is  carefully  regulated  at  first,  as  the  most  useful  hardness 
is  produced  by  that  degree  of  heat  which  is  just  suf¬ 
ficient  to  cllect  the  purpose.  Cast  steel,  annealed  to  a 
straw  colour,  is  softened  nearly  as  much  as  other  kinds  to 
a  purple  or  blue. 

Yrarious  methods  of  hardening  steel  are  resorted  to, 
such  as  oii,  tallow,  urine,  and  other  saline  liquids;  soap 
in  solution  produces  a  similar  effect.  But  when  steel  is 
required  to  possess  the  greatest  degree  of  hardness,  it 
may  be  quenched  in  mercury,  which  will  render  it  so 
hard  as  to  cut  glass  like  a  diamond. 

Wrought  iron  may  be  hardened,  in  a  small  degree,  by 


MECHANICAL  EXERCISES. 


279 


ignition  and  plunging  into  water,  but  the  effect  is  con- 
iined  to  the  surface;  except,  as  very  often  happens,  the 
iron  contains  veins  of  steel. 

The  surest  method  for  selecting  steel  for  edge  tools,  is, 
to  have  one  end  of  the  bar  drawn  out  under  a  low  heat„ 
such  as  an  obscure  red,  and  then  to  plunge  it  suddenly, 
at;  this  heat,  into  a  pure  cold  water.  If  it  prove  hard, 
for  instance,  it  it  will  easily  cut  glass,  and  require  a 
great  force  to  break  it,  whatever  its  fracture  may  be,  it 
is  good,  the  excellence  of  steel  being  always  proportion¬ 
ate  to  the  degree  of  its  tenacity  in  its  hard  state  :  in 
general  a  neat  curved  line  fracture,  and  even  grey  tex¬ 
ture,  denote  good  steel,  and  the  appearance  of  threads, 
cracks,  or  brilliant  specks,  is  a  proof  of  the  contrary. 

If  diluted  nitrous  acid  (aquafortis)  be  applied  to  the 
surface  of  steel  previously  brightened,  it  immediately 
produces  a  black  spot,  but  if  applied  to  iron,  in  like 
manner,  the  metal  remains  clear.  By  this  method  it 
will  be  easy  to  select  such  pieces  of  iron  or  steel  as  pos¬ 
sess  the  greatest  degree  of  uniformity;  as  the  smallest 
vein  of  either  upon  the  surface,  will  be  distinguished  by 
its  peculiar  sign. 

The  hardness  and  polish  of  steel  may  be  united,  in  a 
certain  degree,  with  the  firmness  and  cheapness  of 
malleable  iron,  by  what  is  called  case-hardening,  an 
operation  much  practised,  and  of  considerable  use.  It 
is  a  superficial  conversion  of  iron  into  steel,  and  only 
differs  from  cementation  in  being  carried  on  for  a  shorter 
time:  some  artists  pretend  to  great  secrets  in  the  prac¬ 
tice  of  this  art,  using  saltpetre,  sal  ammoniac,  and  other 
fanciful  ingredients,  to  which  they  attribute  their  success. 
But  it  is  now  an  established  fact,  that  the  greatest  effect 
may  be  produced  by  a  perfectly  tight  box,  and  animal 
carbon  alone. 

The  goods  intended  to  be  case-hardened,  being  pre¬ 
viously  finished  with  the  exception  of  polishing,  are 
stratified  with  animal  carbon,  and  the  box  containing 
them  luted  with  equal  parts  of  sand  and  clay.  They 
are  then  placed  in  the  fire,  and  kept  in  a  light-red  heat 


280 


MECHANICAL  EXERCISES. 


for  half  an  hour, -when  the  contents  of  the  box  are 
emptied  into  water.  Delicate  articles  may  be  preserved 
like  files,  by  a  saturated  solution  of  common  salt  with 
any  vegetable  mucilage  to  give  it  a  pulpy  consistence. 
The  carbon  here  spoken  of,  is  nothing  more  than  any 
animal  matter,  such  as  horns,  hoofs,  skins,  or  leather, 
just  sufficiently  burnt  to  admit  of  being  burnt  to  powder. 
The  box  is  commonly  made  of  iron,  but  the  use  of  it 
for  occasional  case-hardening  upon  a  small  scale  may  be 
easily  dispensed  with ;  as  it  will  answer  the  same  end  to 
envelope  the  articles  with  the  composition  above  direct¬ 
ed  to  be  used  as  a  lute,  drying  it  gradually,  before  it  is 
exposed  to  a  red  heat,  otherwise  it  will  probably  crack. 
It  is  easy  to  infer,  that  the  depth  of  the  steel  induced  by 
case-hardening,  will  vary  with  the  time  the  operation  is 
continued.  In  half  an  hour  it  will  scarcely  be  the 
thickness  of  a  six-cent  piece,  and  therefore  will  be  re¬ 
moved  by  the  violent  abrasion,  though  sufficient  to 
answer  well  for  fire-irons,  etc.,  in  the  common  usage  of 
which  its  hardness  prevents  its  being  easily  scratched, 
and  its  polish  is  preserved  by  friction  with  so  soft  a  ma 
terial  as  leather. 

The  blueing  of  steel  has  a  remarkable  influence  on 
its  elasticity.  This  operation  consists  in  exposing  steel, 
the  surface  of  which  has  been  brightened,  to  the  regu¬ 
lated  heat  of  a  plate  of  metal,  or  of  a  fire,  or  lamp,  till 
the  surface  has  acquired  a  blue  colour.  If  this  blue 
colour,  so  commonly  considered  rather  as  ornamental 
than  useful,  be  partially  or  wholly  removed,  by  grinding 
or  in  any  other  manner,  the  elasticity  is  proportionately 
impaired,  and  the  original  excellence  of  this  property 
can  only  be  restored  by  blueing  the  steel  again.  Saw* 
makers  first  harden  their  plates  in  the  usual  way,  in 
which  state  they  are  brittle  and  warped ;  they  then 
soften  them  by  blazing,  which  consists  in  smearing  the 
plate  with  oil  or  grease,  and  heating  it  till  thick  vapours 
are  emitted,  and  burn  olF  with  a  blaze.  They  then 
hammer  them  flat,  and  afterwards  blue  them  on  a  hot 
•run,  which  renders  them  still'  and  elastic,  without  alter¬ 
ing  their  flatness. 


MECHANICAL  EXERCISES.  281 

Steel  expands  its  dimensions,  in  a  small  degree,  by 
hardening.  It  is  a  curious  fact,  that  intense  cold  has 
an  unfavourable  effect  on  steel;  so  that,  in  severe  frosts, 
workmen  often  find  their  tools  incapable  of  receiving  the 
temper  they  wish. 

A  slender  rod  of  wrought  iron  may  be  expeditiously 
converted  into  steel,  by  plunging  it  into  cast  iron  in  fu¬ 
sion  ;  a  satisfactory  proof  that  cast  iron  contains  the  steel¬ 
making  principle,  which,  we  need  not  repeat,  is  carbon. 
In  fact,  as  it  is  principally  in  the  superabundance  of  its 
carbon  that  it  differs  from  steel,  many  attempts,  (and 
not  without  success,)  have  been  made  to  convert  it  into 
the  latter,  without  the  intermediate  operation  of  render¬ 
ing  it  malleable.  But  the  best  steel  made  pursuant  to 
this  idea,  is  very  imperfect.  It  is,  however,  not  unim¬ 
portant  to  observe,  that  all  cast  iron  so  far  resembles 
steel,  as  to  be  hardened  in  a  high  degree  by  sudden  cool¬ 
ing,  which  imparts  to  it,  at  the  same  time,  whiteness  of 
colour,  brittleness,  and  closeness  of  texture.  This  pro¬ 
perty  of  crude  iron  may  be  advantageously  employed  on 
many  occasions ;  for  instance,  in  the  fabrication  of  axles, 
and  collars  of  wheels,  which  are  closely  turned  or  filed 
in  a  thin  soft  state,  and  may  afterwards  be  hardened,  so 
as  to  wear  admirably  well. 

The  heat  applied  to  cast  iron,  previously  to  its  being 
plunged  into  the  water  to  harden,  is  greater  than  that  to 
which  steel  is  subjected  for  the  same  purpose.  Cast  iron, 
also,  when  once  hardened,  admits  not,  like  steel,  of  that 
hardness  being  reduced,  by  various  gradations,  to  any 
specific  degree ;  to  soften  it  materially,  it  must  be  sub¬ 
mitted,  for  some  time,  to  a  ^omplete  ignition,  and  very 
gradually  cooled. 

ANEALING. 

In  a  considerable  number  of  instances,  bodies  which 
are  capable  of  undergoing  ignition,  are  rendered  hard 
and  brittle  by  sudden  cooling.  Glass,  cast  iron,  and  steel, 
are  the  most  remarkably  affected  by  this  circumstance  ; 
the  inconveniences  arising  Irorn  which  are  obviated  by 
24  * 


iVi  E  C  H  A  N 1 C  A  L  EXERCISES. 


OQO 

cooling  (hem  very  gradually,  and  this  process  is  called 
annealing.  Glass  vessels  are  carried  into  an  oven  over 
the  great  furnace  called  the  leer,  where  they  are  per¬ 
mitted  to  cool,  in  a  greater  or  less  time,  according  to 
their  thickness  and  bulk.  Steel  is  most  effectually 
anealed  by  making  it  red-hot  in  a  charcoal  fire,  which 
must  completely  cover  it,  and  be  allowed  to  go  out  of  its 
own  accord.  Cast  iron,  which  may  require  to  be  an¬ 
nealed  in  too  large  a  quantity,  to  render  the  expense  of 
charcoal  very  agreeable,  may  be  heated  in  a  cinder  fire, 
which  must  completely  envelope  and  defend  the  pieces 
from  the  air  till  they  are  cold.  The  fire  need  not  be 
urged  so  as  to  produce  more  than  a  red  heat;  a  little 
beyond  this,  bars  and  thin  pieces  w'ould  bend,  if  destitute 
of  a  solid  support;  and  would  even  be  melted  without 
any  vehement  degree  of  heat.  If  it  be  required  to  aneal 
a  number  of  pieces  expeditiously,  and  the  fire  is  not 
large  enough  to  take  more  than  one  or  two  of  them  at 
once ;  or  if  it  be  thought  hazardous  to  leave  the  fire  to 
itself,  from  an  apprehension  that  the  heat  might  increase 
too  much,  the  following  scheme  may  be  adopted :  heat  as 
many  of  the  pieces  at  once  as  may  be  convenient,  and 
as  soon  as  they  are  red-hot,  bury  them  in  the  dry  saw¬ 
dust.  Cast  iron,  when  anealed,  is  less  liable  to  warp 
by  a  subsequent  partial  exposure  to  moderate  degrees 
ot  heat,  than  that  which  has  not  undergone  this  opera¬ 
tion. 

The  above  methods  of  anealing  render  cast  iron  easy 
to  work,  but  do  not  deprive  it  of  its  natural  character 
Cast  iron  cutlery  is,  therefore,  stratified  with  some  sub¬ 
stance  containing  oxygen,  such  as  poor  iron  ores,  free 
from  sulphur,  and  kept  in  a  state  little  short  of  fusion  for 
twenty-four  hours.  It  is  then  found  to  possess  a  consider¬ 
able  degree  of  malleability,  and  is  not  unfit  for  several 
sorts  of  nails  and  edge-tools. 

Copper  forms  a  remarkable  exception  to  the  general 
rule  of  anealing.  This  metal  is  actually  made  softer 
and  more  flexible  by  plunging  it,  when  red-hot,  into  cold 
water,  than  by  any  other  means.  Gradual  cooling  pi  v 
duces  a  contrary  effect. 


MECHANICAL  EXERCISES. 


283 


COPPER. 

We  refer  to  the  article  of  chemistry  for  a  minute  enu¬ 
meration  of  the  whole  of  the  known  metals;  but  in  this 
place,  we  shall,  with  the  exception  of  iron,  which  has 
already  been  noticed,  introduce  a  general  practical  view 
ot  the  properties,  applications,  and  combinations  with 
each  other,  of  those  most  frequently  occurring  in  common 
arts  and  common  life.  Making  this  our  plan,  the  firs 
object  that  claims  our  attention  is  copper. 

Copper  is  a  very  brilliant,  sonorous  metal,  of  a  fine 
colour,  possessing  a  considerable  degree  of  hardness  and 
elasticity.  It  is  extremely  malleable,  and  may  be  re¬ 
duced  to  leaves  so  fine,  that  they  may  be  carried  about 
by  the  wind.  Its  tenacity  is  very  great.  A  wire  of 
one-tenth  of  an  inch  in  diameter  will  support  a  weight 
equal  to  300  lbs.  avoirdupois,  without  breaking.  It  does 
not  melt  till  the  temperature  is  elevated  to  about  27°  of 
Wedgwood;  or,  (by  estimation)  14.50°  of  Fahrenheit. 
When  rapidly  cooled,  it  exhibits  a  granulated  and  porous 
texture.  When  the  texture  is  raised  beyond  what  is 
necessary  for  its  fusion,  it  is  sublimed  in  the  form  of  visi¬ 
ble  lumes.  Its  greatest  malleability  is  at  a  low  red  heat. 
None  of  the  malleable  metals  are  so  difficult  to  file,  or 
turn  smooth,  as  copper;  but  it  is  cut  by  the  graver,  or 
ground  by  gritty  substances,  with  great  ease. 

When  miners  wish  to  know'  whether  an  ore  contains 
copper,  they  drop  a  little  nitric  acid  upon  it ;  after  a 
little  lime,  they  drop  a  feather  into  the  acid,  and  wipe  it 
over  the  polished  blade  of  a  knife;  if  there  be  the 
smallest  quantity  of  copper  in  it,  this  metal  will  be  pre-_ 
cipitated  upon  the  knife,  to  which  it  will  impart  a  pecu¬ 
liar  colour.  Roman  vitriol,  much  used  by  dyers,  and  in 
many  of  the  arts,  is  a  sulphate  of  copper.  A  solution  of 
this  salt  is  used  for  browning  fowling-pieces  and  tea-urns. 
In  domestic  economy,  the  necessity  of  keeping  copper 
vessels  perfectly  clean,  cannot  be  too  strongly  inculcated 
but  it  is  worthy  of  remark  that  fat  and  oily  substances, 
and  vegetable  acids,  do  not  attack  copper  while  hot ;  and, 


284 


MECHANICAL  EXERCISES. 


therefore,  copper  vessels  may  he  used,  for  culinary  pur* 
poses,  with  perfect  safety,  if  no  liquor  be  ever  suffered 
to  grow  cold  in  them.  The  mere  tinning  of  copper  and 
brass  vessels  docs  not  allord  complete  safety,  as  it  is  never 
so  perfect  as  to  cover  every  part. 

Compounds  formed  by  the  mixture  of  two  .  or  more 
different  metals  are  called  alloys.  The  alloys  of  copper, 
especially  those  in  which  this  metal  predominates,  are 
more  numerous  in  the  arts  than  those  of  any  other 
metal.  Many  of  them  are  perfectly  well  known,  and  have 
been  immemorially  in  use.  The  exact  composition,  and 
particularly  the  mode  of  preparing  several,  are  kept  as 
secret  as  possible.  By  the  aid  of  chemistry,  we  may 
detect  the  exact  composition  of  an  alloy ;  yet  we  may 
not  always  be  able,  by  common  methods,  to  produce  a 
mixture  having  all  the  excellencies,  which  perhaps, 
mere  accident  has  taught  the  possessor  of  the  secret  to 
combine. 

Brass  is  the  most  important  of  all  the  alloys  of  copper. 
It  is  more  fusible  than  copper,  less  liable  to  tarnish  from' 
exposure  to  the  atmosphere,  and  its  fine  yellow  colour  is 
more  agreeable  to  the  eye.  It  is  much  more  malleable 
than  copper,  when  cold,  but  less  malleable  when  hot;  at 
a  low  red  lveat,  it  crumbles  under  the  hammer.  Sieves 
of  extreme  fineness  are  woven  with  brass  wire,  after  the 
manner  of  cambric  weaving  which  could  not  possibly  be 
made  with  copper  wire.  Three  parts  of  copper  and  one 
of  calamine,  or  native  carbonate  of  zinc,  constitute  brass. 
The  calamine  is  first  pounded  in  a  stamping  mill,  and 
then  washed  and  sifted,  in  order  to  separate  the  lead 
with  which  it  is  mixed.  It  is  then  calcined  on  a  broad, 
shallow  brick  earth,  over  an  oven  heated  to  redness,  and 
frequently  stewed  for  some  hours.  In  some  places,  it  is 
calcined  in  a  kind  of  kiln,  filled  with  alternate  layers  of 
calamine  and  charcoal,  and  kindled  from  the  bottom, 
where  a  sufficient  quantify  of  wood  has  been  deposited 
for  the  purpose.  When  the  calamine  lias  been  thoroughly 
calcined,  it  is  ground  in  a  mill,  and  mixed  at  the  same 
time  with  a  third  or  a  fourth  part  of  charcoal,  and  is 


MECHANICAL  EXERCISES. 


285 


then  ready  for  the  brass  furnace.  Being  put  into  cru 
cibles  with  the  requisite  proportion  of  grain  copper 
copper  chippings,  or  refuse  bits  of  various  kinds,  the 
whole  is  covered  with  charcoal,  and  the  crucibles  luted 
up  with  a  mixture  of  clay  or  loam  and  horse-dung.  The 
heat  employed,  is,  for  a  considerable  time,  not  sufficient 
to  melt  the  copper,  which  is  at  length  raised  so  as  tc 
fuse,  and  the  compound  metal  is  then  run  into  ingots. 

In  general,  the  extremes  of  the  highest  and  lowest 
proportions  of  zinc  are  from  twelve  to  twenty-five  per 
cent,  of  zinc  ;  brass  is  perfectly  malleable,  if  .well  man- 
afactured,  though  zinc  itself  scarcely  yields  to  the  hammer 
it  common  temperatures. 

Good  brass,  when  received  from  the  foundry,  is  nearly 
inelastic,  but  exceedingly  flexible,  and  when  polished, 
the  naked  eye  cannot  discover  any  pores,  which  are  fre¬ 
quently  observable  in  the  inferior  kinds.  The  libera) 
use  of  the  hammer  imparts  a  considerable  portion  of 
elasticity  to  brass,  and  renders  it  at  the  same  time  less 
flexible.  Clock-makers,  watch-makers,  and  all  artists  who 
employ  this  melal,  put  it  in  forms  that  admit  of  hammer¬ 
ing  it  well  before  they  turn  or  file  it ;  otherwise  their 
work  would  wear  indifferently,  and  a  trifling  cause  injure 
its  figure.  Brass  is  not  malleable  when  ignited. 

Hammering  is  found  to  give  a  magnetic  property  to 
brass,  perhaps  occasioned  by  the  minute  particles  of  iron 
separated  from  the  hammer  and  the  anvil  during  the 
process,  and  forced  into  its  surface.  This  circumstance 
makes  it  necessary  to  employ  unhammered  brass  for 
compass  boxes  and  similar  apparatus. 

Five  or  six  parts  of  copper  and  one  of  zinc,  form  a 
pinchbeck.  Tombac  has  still  more  copper,  and  is  of  a 
deeper  red  than  pinchbeck.  Prince’s  metal  is  a  similar 
compound,  excepting  that  it  contains  more  zinc  than 
either  of  the  former. 

The  alloys  of  copper  with  different  proportions  of  tin, 
are  of  great  importance  in  the  arts.  They  form  com¬ 
pounds  which  have  distinct  and  appropriate  uses.  Tin 
renders  copper  more  fusible,  less  liable  to  rust,  harder, 


280 


MECHANICAL  EXE11C1SES. 


denser,  and  more  sonorous.  Copper  and  tin  separately 
are  not  more  remarkable  for  their  ductility,  than,  when 
united,  the  compounds  they  form  are  for  their  brittleness. 

Eight  to  ten  parts  of  tin,  combined  with  one* hundred 
parts  of  copper,  form  bronze,  which  is  of  a  greyish 
yellow  colour,  harder  than  copper,  and  the  usual  compo¬ 
sition  for  statues. 

The  customary  proportions  for  bell-metal  are,  three 
parts  of  copper  and  one  of  tin.  The  greater  part  of  the 
tin  may  be  separated  by  melting  the  alloy,  and  then 
throwng  a  little  water  upon  it.  The  tin  decomposes  the 
water,  is  oxidized,  and  thrown  upon  the  surface.  The 
proportion  of  tin  in  bell-metal  is  varied  a  little  at  diifer- 
ent  foundries,  and  for  different  sorts  of  bells.  Less  tin  is 
used  for  large  bells  than  smaller  ones,  and  for  very  small 
ones,  a  trilling  quantity  of  zinc  is  used,  which  renders 
the  composition  more  sonorous,  and  it  is  still  further 
improved  in  this  respect  by  a  little  silver  being  added. 

A  small  quantity  of  antimony  is  occasionally  found  in 
bell-metal.  When  copper,  brass,  and  tin,  are  used  to 
form  bell-metal,  the  copper  is  from  seventy  to  eighty  per 
cent.,  including  the  proportion  contained  in  the  brass,  and 
the  remainder  is  tin  and  zinc.  W  hen  tin  is  nearly  one- 
third  of  the  alloy,  it  is  then  beautifully  white,  with  a 
lustre  almost  like  mercury,  extremely  hard,  close-grained, 
and  brittle;,  but  when  the  proportion  of  tin  is  one-half, 
it  possesses  these  properties  in  a  still  more  remarkable 
degree,  and  is  susceptible  of  so  exquisite  a  polish,  as  to 
be  admirably  adapted  for  the  speculums  of  telescopes. 
If  more  tin  be  added  than  amounts  to  half  the  weight 
of  the  copper,  the  alloy  begins  to  lose  that  splendid 
w lateness  tor  which  it  is  so  valuable  as  a  mirror,  and 
becomes  of  a  blue  grey.  As  the  quantity  of  tin  is  in- 
r eased,  the  texture  becomes  rough-grained,  and  totally 
unfit  for  manufacture. 

OF  TIN. 

I  in  is  a  metal  of  considerable  importance  in  the  arts. 
It  is  of  a  silver-white  colour,  very  ductile,  malleable,  and 


MECHANICAL  EXERCISES.  287 

gives  out  while  bending,  a  peculiar  crackling  noise.  Its 
specific  gravity  is  7.291  ;  a  cubic  foot  weighs  about 
51G  lbs.  avordupois.  Its  purity  is  in  proportion  to  its 
levity.  It  melts  at  the  400th  degree  of  Fahrenheit’s  ther¬ 
mometer,  and  promotes  the  fusibility  of  the  metals  with 
which  it  is  mixed.  Two  parts  lead  and  one  of  tin  form 
plumbers’  solder,  which  melts  sooner  than  either  of  the 
metals  separately.  Eight  parts  of  bismuth,  five  of  lead, 
and  three  of  tin,  form  a  metal  which  melts  at  a  heat 
not  exceeding  that  of  boiling  water. 

Tin  is  used  to  form  boilers  for  dyers,  and  worms  for 
rectifiers’  stills.  The  common  mixture  for  pewter  is  112 
lbs.  of  tin,  15  lbs.  of  lead,  and  6  lbs.  of  brass.  But  the 
name  of  pewter  is  given  to  any  malleable  white  alloy 
into  which  tin  largely  enters ;  and  perhaps  no  two  manu¬ 
facturers  employ  the  same  ingredients  in  the  same  pro¬ 
portions.  The  finest  kinds  of  pewter  contain  no  lead 
whatever ;  but  consist  ot  tin,  with  a  small  quantity  of 
antimony,  and  sometimes,  a  little  copper.  Pewter  may 
be  used  for  vessels  containing  wine,  and  even  vinegar, 
provided  the  tin  constitutes  three-fifths  of  the  alloy. 

The  consumption  of  tin,  in  the  operation  called  tinning 
is  very  considerable.  The  principal  secret  in  tinning  is, 
to  preserve  the  tin  and  surface  of  the  metal  to  which  it 
is  intended  to  be  applied,  perfectly  clean,  and  in  a  pure 
metallic  state.  Thin  plates  or  sheets  of  iron,  which, 
when  coated  with  tin,  are  so  well  known  under  the 
name  of  tin-plates,  white  iron,  or  latten,  are  prepared  by 
scouring  them  with  sand.  They  are  then  immersed  in 
water,  acidulated  with  sulphuric  acid,  in  which  they  are 
kept  for  twenty-four  hours,  being  occasionally  turned 
during  that  time,  so  that  they  may  rust  equally  in  every 
part.  When  taken  out,  they  are  scoured,  and  made 
perfectly  clean ;  they  are  then  dipped  in  pure  water, 
and  kept  till  wanted  for  tinning.  The  tin  is  melted  in 
an  iron  crucible,  narrow,  but  deeper  than  the  length  of 
the  iron  plates,  which  are  plunged  in  downright,  so  that 
the  tin  swims  over  them.  The  surface  of  the  tin,  to 
prevent  its.  oxidation,  is  covered  with  some  oily  or  resin¬ 
ous  matter. 


288 


MECHANICAL  EXERCISES. 


Reaumur  states,  that  the  Germans  cover  it  with  suet, 
previously  prepared  by  frying  and  burning,  which  sur¬ 
prisingly  puts  the  iron  in  a  condition  to  receive  the  tin. 

1  he  melted  tin  must  also  have  a  certain  degree  of  heat. 
If  not  hot  enough,  it  will  not  adhere  to  the  iron;  and,  if 
it  be  too  hot,  the  coat  will  be  very  thin,  and  the  plates 
discoloured.  Plates  intended  to  have  a  very  thick  coat, 
arc  first  dipped  into  the  crucible  when  the  tin  is  very 
hot,  and  afterwards,  when  it  is  cooler.  For  the  second 
dipping,  the  suet  must  not  be  prepared,  but  used  in  its 
common  state.  The  tin  not  only  adheres  to  the  surface 
of  iron  plates,  but  penetrates,  and  intimately  combines 
with  them. 

Copper  is  tinned  after  it  has  been  formed  into  utensils. 
If  the  copper  be  new,  its  surface  is  first  scoured  with 
salt  and  diluted  sulphuric  acid;  pulverised  resin  is  then 
thrown  over  the  interior  of  the  vessel,  into  which,  after 
heating  it  to  a  considerable  degree,  a  sufficient  quantity 
of  melted  tin  is  poured,  and  spread  upon  it,  by  means  of 
a  rod  of  hard-twisted  flax ;  which  renders  the  coating 
uniform.  Pure  tin  is  rarely  used  for  this  purpose;  it  is 
generally,  though  injuriously,  alloyed  with  a  small  pro¬ 
portion  of  lead.  T  he  use  o*l  the  resin  is  important ;  for 
the  heat  given  to  the  copper  is  sufficient  to  oxidize  its 
surface  in  some  degree  ;  and  an  alteration  of  this  sort,  ' 
however  slight,  would  prevent  the  perfect  adhesion  of 
the  tin.  The  resin  is  equally  useful  in  preventing  tlie 
partial  oxidation  of  the  tin,  or  in  reviving  the  small  par¬ 
ticles  of  oxide  which  may  be  formed  during  the  ope¬ 
ration. 

for  tinning  old  vessels  a  second  time,  the  surface  is 
first  scraped  clean  and  bright  with  a  steel  instrument,  oi 
scoured  with  iron  scales,  then  pulverised  salarnmoniac  is 
strewed  over  it,  and  the  melted  tin  is  rubbed  on  the  sur 
face  with  a  solid  piece  of  salarnmoniac. 

The  process  for  covering  iron  vessels  with  tin,  corre¬ 
sponds  with  that  last  described ;  but  they  ought  to  be 
previously  cleaned  with  the  muriatic  acid,  instead  of 
being  scraped  or  scoured.  Iron  nails  which  cannot  be 


MECHANICAL  EXERCISES. 


289 

conveniently  tinned  in  a  bath,  are  easily  covered  with  tin 
by  including  them,  with  a  due  proportion  of  tin  and 
salammoniac,  in  a  stone  bottle,  and  agitating  them  while 
heating  and  cooling. 

The  following  method  of  tinning  is  highly  esteemed  for 
its  permanency  and  beauty :  the  utensil  is  cleaned  in  the 
usual  manner ;  its  inner  surface  is  beaten  on  a  rough 
anvil,  or  scratched  with  a  wire-brush,  that  the  tinning 
may  adhere  more  closely  to  the  copper;  and  one  coat  of 
fine  tin  is  then  laid  on  with  salammoniac  as  above  directed 
for  tinning  old  copper.  A  second  coat  consisting  of  two 
parts  of  tin  and  three  of  zinc,  must  next  be  uniformly 
applied  with  salammoniac,  in  a  similar  manner :  the  sur¬ 
face  is  now  to  be  beaten;  scoured  with  chalk  and  water; 
smoothed  with  a  proper  hammer ;  exposed  to  a  moderate 
heat ;  and  lastly  dipped  in  melted  tin.  This  sort  of  tin¬ 
ning  effectually  prevents  the  utensils  from  rusting. 

Pins  are  whitened  by  filling  a  pan  with’  alternate  lay¬ 
ers  of  them  and  grain-tin.  A  solution  of  super- tartrate 
)f  potass,  (cream  of  tartar)  is  then  poured  upon  them, 
and  they  are  boiled  for  four  or  five  hours.  The  tartaric 
acid  first  dissolves  the  tin,  and  then  gradually  deposits  it 
on  the  surface  of  the  pins,  in  consequence  of  its  greater 
affinity  for  the  zinc  which  enters  into  the  composition  of 
the  brass  wire. 

There  are  two  kinds  of  tin  known  in  commerce ;  viz. 
block  tin,  and  grain  tin.  Block  tin  is  procured  from  the 
common  tin  ore ;  grain  tin  is  found,  in  small  particles,  in 
what  is  called  stream  tin  ore.  It  owes  its  superiority  not 
only  to  the  purity  of  the  ore,  but  to  the  care  with  which 
it  is  washed  and  refined. 

OF  LEAD. 

Lead  unites  with  most  of  the  metals.  It  has  little 
elasticity,  and  is  the  softest  of  them  all.  Gold  and  silver 
are  dissolved  by  it  in  a  slight  red  heat ;  but,  when  the 
heat  is  much  increased,  the  lead  separates,  and  rises  to 
the  surface  of  the  gold,  combined  with  all  heterogeneous 
25  T 


290 


MECHANICAL  EXERCISES. 


matters.  This  property  of  lead  is  made  use  of  in  the 
art  of  refining  the  precious  metals. 

If  lead  be  heated  so  as  to  boil  and  smoke,  it  soon  dis¬ 
solves  pieces  of  copper  thrown  into  it :  the  mixture, 
when  cold,  is  brittle.  The  union  of  these  two  metals 
is  remarkably  slight ;  for,  upon  exposing  the  mass  to  a 
heat  no  greater  than  that  in  which  lead  melts,  the  lead 
almost  entirely  runs  off  by  itself.  This  process,  which 
is  peculiar  to  lead  with  copper,  is  called  eliquation.  It 
has  lately  been  discovered,  that  a  certain  preparation 
of  lead  may  be  mixed  with  the  metal  formerly  used  for 
white  metal  buttons,  without  injuring  the  appearance; 
thus  affording  a  considerable  addition  of  profit  to  the 
manufacturer. 

The  consumption  of  lead  for  water-pipes,  cisterns,  and 
to  cover  buildings,  is  very  extensive.  Sheet-lead  is  made 
by  suffering  the  melted  metal  to  run  out  of  a  box  through 
a  long  horizontal  slit,  upon  a  table  prepared  for  the  pur¬ 
pose.  The  table  is  generally  covered  with  sand,  and 
the  box  is  drawn  over  it  by  appropriate  ropes  and  pul¬ 
leys,  leaving  the  melted  lead  behind,  to  congeal  in  the 
desired  form.  The  requisite  uniformity  and  thinness  are 
given  to  these  sheets,  by  rolling  them  between  two  cylin¬ 
ders  of  iron,  acting  upon  the  same  principle  as  the  cop¬ 
per-plate  printing-press. 

The  alloy  of  lead  and  antimony  is  used  for  printers’ 
types.  Chaptal  made  a  great  variety  of  experiments  to 
ascertain  the  best  proportions  of  these  metals  to  each 
Dther  for  this  use.  lie  always  found  four  parts  of  lead 
and  one  of  antimony  form  the  most  perfect  composition. 
But,  if  the  antimony  be  pure,  one  part  of  it,  to  seven  or 
eight  of  lead,  form  an  alloy  too  brittle  to  be  extended 
under  the  hammer,  and  as  hard  as  the  generality  of 
types.  To  give  hardness  to  the  lead,  is  not  the  only  use 
of  antimony  in  this  composition.  It  renders  the  lead 
more  fusible,  more  fluid  when  melted,  and,  ns  it  expands 
m  passing  to  a  solid  state,  it  is  calculated  to  produce  a 
sharper  impression  of  the  mould  than  could  be  easily 
obtained  by  lead  alone.  Antimony,  (which  in  trade  is 


MECHANICAL  EXERCISES.  291 

•emetimes  called  regulus  of  antimony,  or  regulus,  only,} 
requires,  when  alone,  much  more  heat  for  its  fusion  than 
lead,  in  combining  with  which  metal,  as  it  is  little  more 
than  half  its  weight,  it  rises  to  the  surface,  and  requires 
to  he  well  stirred  before  it  will  incorporate.  Different 
parts  of  the  same  block  of  type-metal  often  possess  dif¬ 
ferent  degrees  of  hardness.  In  melting  lead  for  shot,  a 
small  quantity  of  arsenic  is  added,  to  cause  it  to  run  into 
spherical  drops.  The  arsenic  is  generally  added  in  ex¬ 
cess  to  a  small  quantity  of  lead,  which  is  covered  and 
closely  luted  till  the  incorporation  is  complete.  The 
compound  is  called  slag,  or  poisoned  metal.  Ingots  of 
this  slag  are  then  added  to  soft  pig-lead,  in  such  propor¬ 
tion  as  is  found,  upon  trial,  to  cause  it  to  drop  in  a  globu¬ 
lar  form. 

The  surface  of  melted  lead,  as  every  one  knows,  be¬ 
comes  quickly  covered  with  a  skin  or  pellicle,  often 
assuming  different  lively  hues  at  first,  and  subsequently 
increasing  in  quantity  and  darkness  of  colour.  This 
effect  is  termed  by  chemists,  oxidation,  as  it  is  occasioned 
by  the  action  of  oxygen  of  the  atmosphere,  the  activity 
of  which  is  greater  in  proportion  to  the  heat  of  the  lead, 
•and  wastes  the  metal  so  fast,  that  it  becomes  an  object  of 
importance  to  those  who  melt  much  lead,  to  check  its 
formation,  or  to  convert  it,  when  formed,  by  the  cheapest 
process  into  the  metallic  state  again.  A  thick  coating 
of  ashes  of  any  kind  will  check  the  formation  of  the 
oxide,  and  may  be  easily  pushed  back,  when  a  quantity 
of  lead  must  be  taken  out  of  the  crucible  or  melting-pan. 
Charcoal,  which  is  also  a  good  covering  for  lead  in  the 
pan,  will  convert  dross  into  metal,  when  assisted  by  a 
sufficient  heat ;  fat,  oily,  and  bituminous  substances  in 
general,  have  a  similar  effect.  Common  resin  answers 
exceeding  well  ;  thrown  in  powder  upon  melted  lead, 
and  stirred  about,  it  immediately  converts  the  oxide  into 
metal,  causes  the  surface  to  shine  like  mercurv,  and  if  any 
thing  remains,  it  is  only  a  black  dirt,  with  small  globules 
of  pure  lead,  skimmed  off  at  the  same  time,  yet  mixed 
with  it;  by  throwing  it  into  water,  stirring  it  thoroughly 


292  MECHANICAL  EXERCISES. 

and  pouring  off  all  that  does  not  immediately  sink,  these 
grains  may  be  separated.  If  part  of  what  appears  to 
be  dirt,  is  "found  to  be  so  heavy,  as  instantly  to  sink  to 
the  bottom  of  water,  it  may  be  suspected  to  be  true  dross 
or  oxide,  and  may  be  revived  by  mixing  it  with  charcoa  , 
and  exposing  it  to  a  considerable  heat.  It  is  always, 
however,  more  prudent  and  economical  to  use  means  ot 
preventing  the  formation  of  oxide,  than  to  bestow  much 

time  upon  its  revival.  .  . 

Lead  becomes  less  fluid  every  time  it  is  melted,  and  by 
much  or  frequent  exposure  to  a  high  temperature,  a 
state  in  which  it  is  said  to  he  rotten,  is  superinduced. 
To  use  new  lead,  and  not  melt  it  oftencr,  or  expose  it  to 
a  greater  heat  than  is  indispensable,  are  necessary  pre¬ 
cautions  to  preserve  this  metal  in  its  best  state.  Plumbers, 
when  they  cast  it  into  sheets,  strew  common  salt  upon 
the  table,  to  facilitate  its  spreading,  when  they  are  not 
using  new  lead,  and  are  for  that,  or  any  other  reason, 
apprehensive  that  it  will  not  run  well. 

The  observations  above  recited  on  the  management 
of  lead,  apply  with  equal  propriety,  to  tin,  antimony, 
zinc,  bismuth,  &c.,  and  all  the  alloys  of  these  metals 
with  lead  or  each  other.  In  fact,  as  lead  is  so  much 
cheaper  than  the  other  metals  just  enumerated,  the  ob¬ 
ject  of  saving  it  from  destruction  is  proportionately  ot 
less  consequence. 

OF  ZINC. 

Zinc  is  a  very  combustible  metal,  of  a  bluish,  brilliant 
white  colour.  It  seems  to  form  the  link  between  the 
brittle-  and  the  malleable  metals.  It  is  a  modern  ^dis¬ 
covery,  that  at  a  temperature  of  from  210°  to  300°  of 
Fahrenheit,  it  yields  to  the  hammer,  may  be  drawn  into 
„  wire,  or  extended  into  sheets.  After  having  been,, thus 
annealed,  it  continues  soft,  flexible,  and  extensible,  and 
does  not  return  to  its  partial  brittleness;  thus  admitting 
of  being  applied  to  many  uses  for  which  zinc  was  for¬ 
merly  deemed  unfit. 

There  cau  now  be  no  difficulty  in  forming  zinc  into 


MECHANICAL  EXERCISES. 


293 


sheathing  for  the  bottoms  of  ships,  into  vessels  of  capa¬ 
city,  water  pipes,  and  utensils  for  various  manufactories. 
As  an  internal  lining  for  ordinary  vessels,  instead  of  tin, 
it  has  been  applied  with  success.  It  is  much  harder  and 
cheaper  than  tin,  and  may  be  spread  very  uniformly. 

Zinc  at  a  very  elevated  temperature,  may  be  pulver¬ 
ized.  It  may  also,  like  several  other  metals,  be  minutely 
divided,  by  pouring  it,  when  in  fusion,  into  water.  These 
are  the  most  convenient  means  of  reducing  it  into  small 
particles.  Files  have  no  considerable  action  upon  it ; 
besides,  it  wears  and  chokes  them  up  in  a  short  time. 
Zinc,  in  filings  or  small  particles,  is  used  to  produce  those 
brilliant  stars  and  spangles  which  are  seen  in  the  best 
Artificial  fire-works  ;  but  the  filings  of  cast  iron  produce, 
at  a  cheaper  rate,  an  effect  scarcely  inferior. 

Calamine,  or  lapis  calaminarus,  used  in  converting 
copper  into  brass,  is  found  in  masses  and  in  a  crystallized 
state,  and  is  generally  combined  with  a  large  portion  of 
silex.  It  is  a  native  oxide  of  zinc,  combined  with  car¬ 
bonic  acid.  Zinc  is  also  found  in  an  ore  called  blena,  or 
as  the  miners  term  it,  Black  Jack.  It  is  a  sulphuret  of 
zinc :  in  Wales,  it  was  employed  formerly  in  mending 
the  roads. 

SOLDERING. 

To  unite  two  pieces  of  the  same  or  different  metals, 
by  fusing  some  metallic  substance  upon  them,  is  called 
soldering.  It  is  a  general  rule,  that  the  solder  should  be 
easier  of  fusion  than  the  metal  to  be  soldered  by  it.  It 
is,  in  the  next  place,  desirable,  though  seldom  absolutely 
necessary,  nor  always  attempted,  that  the  solder  and  the 
metal  to  which  it  is  intended  to  be  applied,  should  be  of 
the  same  colour,  and  of  the  same  degree  of  hardness  and 
malleability. 

Solders  are  distinguished  into  two  different  classes,  viz. 
the  hard  and  the  soft  solders.  For  the  hard  solders, 
which  are  ductile,  and  admit  of  being  hammered,  some 
of  the  same  sort  of  metal  as  that  to  be  soldered,  is,  in 
the  greatest  number  of  instances,  alloyed  with  some 
25* 


294 


MECHANICAL  EXERCISES. 


other  which  increases  its  fusibility.  Some  of  the  facts 
already  detailed,  respecting  the  metals,  prove  that  the 
addition  made  with  this  view  need  not  always  be  itself 
easier  of  fusion. 

The  solder  for  platina  is  gold,  and  the  expense  of  it 
will,  therefore,  contribute  to  hinder  the  general  use  of 
platina  vessels,  even  in  chemical  experiments. 

The  hard  solder  for  gold,  is  composed  of  gold  and 
silver:  gold  and  copper;  or  gold,  silver,  and  copper 
Goldsmiths  usually  make  four  kinds,  viz.  solder  of  eight, 
in  which,  to  seven  parts  of  silver,  there  is  one  of  brass 
or  copper;  solder  of  six,  where  only  a  sixth  part  is  cop¬ 
per  ;  solder  of  four,  and  solder  of  three.  But  many  who 
may  have  occasion  to  solder  gold,  cannot  encumber  them¬ 
selves  with  these  varieties. 

For  general  purposes,  therefore,  the  following  composi¬ 
tion  may  be  provided  ;  melt  two  parts  of  gold,  with  one 
)f  silver  and  one  of  copper;  stir  the  mass  well  to  make 
it  uniform,  add  a  little  borax  in  powder,  and  pour  it  out 
immediately.  If  cast  into  very  thin  narrow  slips,  it  will 
be  the  more  handy  for  subsequent  use.  To  cleanse  gold 
which  has  been  soldered,  heat  it  almost  to  ignition,  let  it 
cool,  and  then  boil  it  in  urine  and  sal  ammoniac. 

The  hard  solder  for  silver  may  be  prepared  by  melting 
two  parts  of  silver  with  one  of  brass.  It  must  not  be 
kept  long  in  fusion,  lest  the  zinc  of  the  brass  fly  off  in 
fumes,  if  the  silver  to  be  soldered,  be  alloyed  with 
much  copper,  the  proportion  of  brass  may  be  increased . 
for  example,  the  following  composition  may  be  used  ;  four 
parts  of  silver  and  three  of  brass,  rendered  easy  of  fusion 
by  a  sixteenth  part  of  zinc.  Silver  which  has  been  sol* 
dered,  may  be  cleaned  by  heating  it,  and  letting  it  cool, 
as  directed  for  gold,  but  it  must  be  boiled  in  alum  water 

The  hard  solder  for  copper  and  brass,  is  a  soft  fusible 
sort  of  granulated  brass,  known  to  artists  by  the  name 
of  speltre.  It  consists  of  brass  mixed  with  an  eighth, 
or  a  sixth,  or  even  one-half  of  zinc.  The  braziers  use 
no  other  kind  of  hard  solder.  As  speltre  melts  sooner 
than  common  brass,  it  serves  for  the  solder  of  the  latter 
as  well  as  for  copper. 


MECHANICAL  EXERCISES.  295 

Standard  silver  makes  an  excellent  solder  for  brass, 
ft  is  more  fusible  than  spcfltre,  proportionately  easier  to 
manage,  and  equally  as  durable.  A  slight  demand  for 
silver  solder,  may,  to  many,  be  supplied  at  a  cheap  rate, 
in  consequence  of  the  number  of  the  small  silver  articles 
in  use,  and  which  are  frequently  wearing  out. 

Iron  may  be  soldered  with  copper,  gold,  or  silver 
Brass  or  speltre  is  most  commonly  used,  and  the  opera¬ 
tion  is  then  called  brazing ;  but  a  carbonate  of  the  same 
tnetal,  viz.  the  dark  grey  or  most  fusible  sort  of  pig  iron 
called  No.  1,  is  the  most  durable  solder  that  can  be  used. 
The  pig  iron  loses  some  brittleness,  and  the  malleable 
metal  becomes  harder  in  the  proximity  of  the  parts 
soldered. 

The  parts  upon  which  hard  solder  is  intended  to  ope¬ 
rate,  are  touched  with  a  finely  powdered  borax  moistened 
with  water.  They  must,  also,  as  in  all  soldering  and 
tinning  operations,  be  perfectly  clean.  The  borax 
quickly  running  into  a  kind  of  glass,  promotes  the  fusion 
of  the  solder,  and  preserves  from  oxidation  the  surfaces 
to  which  it  is  applied.  The  pieces  intended  to  be  sol¬ 
dered,  are  fastened  together  with  iron  wire,  or  secured 
by  some  contrivance  having  the  same  effect.  Speltre 
being  composed  of  so  many  grains,  is  apt  to  spread  when 
the  borax  boils  up;  but  just  as  it  becomes  fused,  the 
workmen  bring  it  to  the  place  where  it  is  wanted,  by  a 
slender  iron  rod.  The  flame  of  a  lamp,  directed  by  a 
blow-pipe  against  the  solder  covering  the  intended  joint, 
which  must  be  laid  upon  charcoal,  is  sufficient  for  small 
things.  For  large  work,  a  common  culinary  fire  may  be 
made  to  effect  the  desired  fusion,  though  a  forge  is  still 
more  convenient.  The  fire  should  not  touch  the  work, 
nor  the  ashes  be  allowed  to  fall  upon  it. 

The  soft  solders  melt  easily,  but  are  partly  brittle, 
and  therefore  cannot  be  hammered.  The  solder  for  lead 
is  usually  composed  of  two  parts  of  lead  and  one  of  tin. 
Its  goodness  is  tried  by  melting  it,  and  pouring  about  the 
size  of  a  crown-piece  upon  a  table;  little  shining  stars 
will  arise  upon  it,  if  it  is  good.  By  diminishing  tl*e 


296 


MECHANICAL  EXERCISER. 


•  f 


proportion  of  lead,  we  form  what  is  called  stray  solders 
we  may  also  increase  the  proportion,  which  is  advisable 
when  we  wish  to  solder  vessels  for  containing  acids 
because  lead  is  not  so  easily  corroded  or  dissolved  as  tin 

The  lining  of  tea-chests  has  been  used  for  solder,  as  it 
sometimes  comes  mixed  about  the  right  proportion. 
These  valuable  portions  of  tea-lead  may  be  distinguished 
by  their  brilliancy,  having  suffered  little  from  oxidation  ; 
also,  when  they  principally  consist  of  tin,  by  the  crack¬ 
ing  noise  while  bending ;  which  is  peculiar  to  this 
metal,  and  some  of  the  alloys  into  which  it  largely 
enters. 

The  solder  for  tin  may  consist  of  four  parts  of  pewter, 
one  of  tin,  and  one  of  bismuth,  or  two  parts  of  tin,  and 
one  of  lead :  the  latter  is  a  composition  much  used. 

The  soldering-iron  of  the  tin-plate  workers  is  an  ingot 
of  copper,  flattened  at  the  point,  in  a  pyramidal  form : 
it  is  screwed  or  riveted  to  an  iron  stem  fastened  to  a 
wooden  handle.  The  copper  is  seldom  more  than  four 
or  five  inches  .ong,  and  when  it  is  worn  away,  the  same 
stem  and  handle  arc  used  for  another  piece.  The  bar 
of  copper  is  prepared  for  use,  by  filing  it  bright,  and  tin¬ 
ning  it ;  when  sufficiently  hot,  it  will  melt  and  take  up 
the  solder,  so  as  to  afford  a  ready  means  of  applying  it 
to  the  intended  juncture.  Powdered  rosin,  and  some¬ 
times  pitch,  is  used  along  with  the  soft  solders,  to  pre¬ 
serve  the  metals  employed  from  oxidation. 

Tin-foil,  applied  between  the  joints  of  fine  brass-w'ork, 
first  wetted  with  a  solution  of  sal  ammoniac,  and  held 
firmly  together  while  heated,  makes  an  excellent  junc¬ 
ture,  care  being  taken  to  avoid  too  much  heat. 

OF  GLUE. 

To  prepare  glue,  it  must  be  steeped  for  a  number  of 
hours,  over  night,  for  instance,  in  cold  water,  by  which 
means  it  will  become  considerably  swelled  and  softened. 
It  must  then  be  gently  boiled,  till  it  is  entirely  dissolved, 
and  of  a  consistence  not  too  thick  to  be  easily  brushed 
over  wood.  About  a  quart  of  water  may  be  used  to 


MECHANICAL  EXERCISES.  297 

half  a  pound  of  glue.  The  heat  employed  in  melting 
glue  should  not  be  more  than  is  required  to  make  watei 
boil ;  and  to  avoid  burning  it,  the  workmen,  as  is  well 
known,  suspend  the  vessel  containing  it  in  another  vessel 
containing  only  water,  which  latter  vessel  is  made  in  the 
form  of  a  common  tea-kettle  without  a  spout,  and  alope 
receives  the  direct  action  of  the  fire. 

The  circumstances  most  favourable  to  the  best  effects 
which  glue  can  produce,  in  uniting  two  pieces  of  wood, 
are  the  following:  that  the  glue  should  be  thoroughly 
dissolved,  and  used  boiling  hot  at  the  first  or  s^-eond  melt¬ 
ing;  that  the  wood  should  be  warm  and  p<  ,fectly  dry; 
and  a  very  thin  covering  of  glue  be  inte  posed  at  the 
juncture,  and  that  the  surfaces  to  be  united,  be  strongly 
pressed  together,  and  left  in  that  state  in  a  warm  but 
not  hot  situation,  till  the  glue  be  completely  hard.  In 
veneering,  and  for  very  delicate  work,  the  whole  of  these 
requisites,  as  they  not  only  ensure  the  strongest,  but  the 
glue  sets  the  soonest,  should  be  combined  in  the  opera¬ 
tion  ;  but  on  some  occasions  this  is  impossible,  and,  there¬ 
fore,  the  most  essential  must  be  regarded,  such  as  the 
fitness  of  the  glue,  and  dryness  of  the  wood.  When  the 
faces  of  joints,  particularly  those  that  cannot  be  much 
compressed,  have  been  besmeared  with  glue,  which  should 
always  be  done  with  the  greatest  expedition,  they  should 
be  rubbed  lengthwise  one  upon  another,  two  or  three 
times,  to  settle  them  close. 

When  glue,  by  repeatedly  heating  it,  has  become  of  a 
dark  and  almost  black  colour,  its  qualities  are  impaired  ; 
when  newly  melted,  it  is  of  a  light  ruddy  brown  colour, 
nearly  like  that  of  the  dry  cake  held  up  to  the  light; 
and  while  this  colour  remains,  it  may  be  considered  fit 
for  almost  every  purpose.  Though  glue  which  has  been 
melted  is  the  most  suitable  for  use,  other  circumstances 
being  the  same,  yet  that  which  has  been  the  longest 
manufactured  is  the  best.  To  try  the  goodness  of  glue, 
steep  a  piece  three  or  four  days  in  cold  water;  if  it 
swell  considerably  without  melting,  and  when  taken  out 
resumes,  in  a  short  time,  its  former  dryness,  it  is  excel- 


298  MECHANICAL  EXERCISES. 

lent.  If  it  be  soluble  in  cold  water,  it  is  a  proof  that 
it  wants  strength. 

A  glue  which  does  not  dissolve  in  water,  may  be  ob¬ 
tained  by  melting  a  common  glue  with  the  smallest 
possible  quantity  of  water,  and  adding  by  degrees  lin¬ 
seed  oil  rendered  drying  by  boiling  it  with  litharge; 
while  the  oil  is  added,  the  ingredients  must  be  well  stirred 
to  incorporate  them  thoroughly. 

A  glue  which  will  resist  water,  in  a  considerable  de¬ 
gree,  is  made  by  dissolving  common  glue  in  skimmed 
milk. 

Finely  lixiviated  chalk  added  to  the  common  solution 
of  glue  in  water,  constitutes  an  addition  that  strengthens 
it,  and  renders  it  suitable  for  boards,  or  other  things 
which  must  stand  the  weather. 

A  glue  that  will  hold  against  fire  or  water,  may  be 
prepared  by  mixing  a  handful  of  quick-lime  with  four 
ounces  of  linseed  oil :  thoroughly  lixiviate  the  mixture, 
boil  it  to  a  good  thickness,  and  then  spread  it  on  tin  plates 
in  the  shade;  it  will  become  exceedingly  hard,  but  may 
be  dissolved  over  a  fire,  as  ordinary  glue,  and  is  then  fit 
for  use. 

THE  COMMON  SLIDING  RULE. 

The  divisors  inserted  in  the  following  table,  and  the 
few  plain  directions  and  examples  given,  will  now  render 
it  capable  of  being  applied  to  every  purpose  that  any 
artificer  can  possibly  want.  And  by  taking  a  copy  of 
the  table  upon  a  piece  of  parchment,  and  carrying  it 
always  in  the  pocket,  these  divisors  will  be  at  hand:  and 
the  weight  or  measure  required  may  be  obtained. 

Description  of  the  lines  upon  the  slide  rule. 

Upon  the  sliding  rule  of  this  rule  are  four  lines  mark¬ 
ed  A,  B,  C,  and  I).  The  three  marked  A,  B,  and  C  are 
double  lines  of  numbers,  one  of  which  is  upon  the  rule, 
and  the  other  two  are  upon  the  slide.  That  marked  1) 
is  a  single  line  of  numbers,  commonly  called  the  girt  line 


MECHANICAL  EXERCISES. 


299 


Numeration. 

■  Thesf  four  lines  are  divided  as  follows:  each  of  the 
double  lines  marked  A,  B,  and  C  are  figured  1,  2,  3,  4, 
5,  6,  7,  8,  9 ;  then  again  1,  2,  3,  4,  5,  6,  7,  8,  9,  and  10 
at  the  end.  And  these  figures  may  be  increased  or  de¬ 
creased  in  the  value,  but  always  in  a  tenfold  proportion, 
at  pleasure;  thus  one  at  the  beginning  may  be  called 
either  1,  or  10,  or  100,  or  1000,  and  then  the  one  in  the 
middle  of  the  rule  must  be  called  10,  100, 1000  or  10,000. 
Observe,  from  one  to  two  is  divided  into  10  parts,  and 
each  tenth  is  subdivided  into  5  parts,  and  from  2  to  3  is 
divided  into  ten  parts,  and  each  tenth  into  2  parts,  and 
from  3  to  4  and  so  on  to  10  is  divided  into  10  parts  only 
The  girt  line,  marked  D,  is  figured  4,  5,  6,  7,  8,  9,  10 
12,  15,  20,  25,  30,  35,  and  40  at  the  end. — And  tht 
figures  and  divisors  are  valued  in  tenfold  proportion,  as 
above. 

As  there  have  been  so  many  books  published  for  the 
use  of.this  Rule,  it  is  unnecessary  to  say  much  upon  the 
subject;  because  when  numeration  is  properly  under¬ 
stood,  any  person,  from  these  plain  ‘directions,  may  per¬ 
form  any  operation,  in  superficial  and  solid  mensurations, 
that  may  be  wanted  in  the  common  course  of  business, 
and,  with  the  assistance  of  these  divisors,  may  find  the 
weight  of  any  of  the  articles  contained  in  the  table. 


A  TABLE  OF  DIVISORS 

For  the  use  of  the  common  single  Sliding  Rule. 

The  first  column  contains  the  divisors  for  dimensions 
that  are  taken  feet  long,  feet  wide,  and  feet  thick.  The 
second  column  is  for  dimensions  that  are  taken  feet  long, 
inches  wide  and  thick.  The  third  column  is  for  dimen¬ 
sions  that  are  taken  inches  long,  inches  wide,  and  inches 
thick. 

The  fourth  is  a  column  of  divisors  for  dimensions  that 


300 


MECHANICAL  EXERCISES 


are  taken  feet  long,  and  inches  diameter.  The  fifth 
column  is  for  dimensions  that  are  taken  inches  long  and 
diameter. 

The  six'll  is  a  column  of  divisors  or  diameters,  taken  in 
feet.  The  seventh  column  is  for  diameters  taken  in 
inches. 


Square. 

Cylinders. 

Globes. 

1st. 

2d. 

3d. 

4th. 

5th. 

6th. 

7th. 

Cubic  Inches . 

36 

518 

624 

660 

799 

625 

113 

Cubic  Feet . 

625 

9 

108 

114 

138 

119 

206 

Wine  Gallons . 

835 

12 

145 

153 

183 

16 

276 

Ale  Gallons . 

102 

147 

176 

188 

224 

196 

335 

Water  in  lb . 

10 

144 

174 

184 

22 

191 

329 

Oil  in  lb . 

108 

1565 

189 

199 

238 

207 

358 

Gold  in  lb . 

507 

735 

88 

96 

118 

939 

180 

Silver  in  lb . 

938 

136 

157 

173 

208 

173 

354 

Quicksilver  in  lb . 

738 

122 

127 

132 

162 

141 

242 

Brass  lb . 

12 

174 

207 

221 

265 

23 

397 

Copper  lb . 

112 

163 

196 

207 

247 

214 

371 

Lead  lb . 

880 

126 

152 

1 62 

194 

169 

289 

Wrought  Iron  . 

129 

186 

222 

235 

283 

247 

423 

Cast  Iron  and  Speltre  lb . 

139 

2 

241 

254- 

304 

265 

458 

Tin  lb . 

137 

135 

235 

25 

300 

261 

454 

£>teel  lb . 

136 

183 

22 

233 

278 

239 

418 

Marble  lb . 

370 

53 

637 

725 

81 

72 

121 

Free-stone  lb . 

394 

57 

69 

728 

873 

755 

132 

Brick  lb . 

495 

72 

860 

92 

10 

95 

164 

Coal  lb . 

795 

114 

138 

146 

176 

151 

262 

Dry  Oak  lb . 

108 

158 

190 

2 

237 

208 

355 

Mahogany  lb . 

94 

136 

164 

175 

208 

18 

336 

Box  lb . 

968 

152 

|  169 

194 

214 

186 

32 

Red  Deal  lb . 

151 

22 

1263 

285 

236 

|  287 

501 

EXAMPLES. 

Example  1.  Required  the  content  in  cubic  inches  of  » 
piece  of  timber  2  feet  long,  12  inches  wide,  and  12 
inches  thick ;  see  the  preceding  table  of  divisors  in  the 
line  of  cubic  inches,  second  column,  and  you  will  tina 
the  divisor  for  feet  long,  inches  wide,  and  inches  thick  is 
518,  set  2,  which  is  the  length  upon  B,  to  518,  the  divi- 


MECHANICAL  EXERCISES.  30 1 

sor  upon  A,  against  12,  which  is  the  breadth  and  thickness 
upon  D,  3456,  which  is  the  content  in  inches  on  C. 

Ex.  2  Having  the  dimensions  of  an  unequal  sided 
piece  of  timber  given  to  find  the  mean  square,  which 
must  be  done  in  all  cases  where  the  breadth  and  thick¬ 
ness  are  unequal.  What  is  the  square  of  a  piece  of 
timber  16  inches  broad,  and  four  inches  thick?  Set  16, 
the  breadth  on  C,  to  16  on  D,  and  against  4,  the  thick¬ 
ness  on  C  is  8  inches  the  square  on  D. 

Ex.  3.  Required  the  content  of  a  piece  of  cast  iron 
24  inches  long  and  12  square ;  see  the  preceding  table 
in  the  line  cast  iron  and  speltre,  third  column,  is  divisor 
241  ;  set  24  on  B  to  241  on  A,  and  against  12  on  D  is 
896  on  C. 

Ex.  4.  Required  the  weight  of  a  piece  of  cast  iron 
circular  24  inches  and  12  diameter:  see  the  preceding 
table,  fifth  column,  in  the  line  cast  iron  and  speltre  is  304 
the  divisor;  set  length  on  B  to  the  divisor  on  A,  and 
against  the  diameter  on  D  is  708  lbs.  the  content  on  C. 

Ex.  5.  Required  the  weight  of  a  ball  or  globe  in  cast 
iron  12  inches  in  diameter;  see  the  preceding  table, 
seventh  column,  in  the  line  cast  iron  and  speltre  is  458, 
the  divisor;  set  12  the  diameter  on  B  to  458,  the  divisor 
on  A,  and  against  12  inches  diameter  on  D,  is  235  the 
content  on  C. 

Ex.  6.  Required  the  content  of  a  piece  of  timber  1 
inch  long  and  12  inches  diameter ;  see  the  preceding 
table,  in  the  line  cubic  inches,  fifth  column,  under  cylin¬ 
ders,  the  divisor  is  799;  set  1  inch,  the  length  on  B,  to 
799  on  A,  and  against  12  inches  the  diameter  on  D,  is 
113,  the  content  on  C.  Observe,  when  the  slide  stands 
in  this  position  it  is  a  table  of  areas  of  all  circles,  D  being 
diameters,  or  the  squares  of  diameters,  and  C  being  areas 
or  superficial  inches. 

Ex.  7.  Required  the  content  of  a  piece  of  land,  70 
yards  long,  by  70  wide ;  set  4840  on  A,  the  number  of 
yards  in  an  acre,  to  70  the  length  on  B,  and  against  70 
the  width  on  A  is  1.01  on  B. 

Ex.  8.  Required  the  content  of  a  piece  of  land,  40 
26 


302 


MECHANICAL  EXERCISES. 


poles  long,  and  5  poles  wide;  set  160,  the  number  of 
poles  in  an  acre  on  A,  to  40  the  length  on  B,  and  against 
5,  the  width  on  A  is  1.25  or  1  acre  on  B. 

Ex.  0.  Required  the  diameter  of  a  circle,  whose  area 
is  equal  an  ellipsis  or  oval,  32  by  22  inches  diameter 
set  32  on  C,  to  32  on  D,  and  against  22  on  C  is  26.6 
nearly  on  D. 

Ex.  10.  Required  the  side  of  a  square,  equal  in  pro¬ 
portion  to  a  parallelogram  or  long  square,  32  by  22 
inches ;  set  32  on  C  to  32  on  D,  and  against  22  on  C  is 
26.6  the  mean  proportion  on  D. 

Ex.  11.  Required  the  content  in  roods  of  a  piece  of 
walling,  25  feet  long,  and  10  feet  high ;  set  63,  which  is 
the  number  of  feet  in  a  rood  on  A,  to  25  the  length  on 
B,  and  against  10,  the  height  on  A  is  4  roods  nearly  on  B 

Ex.  12.  Required  the  content  in  roods  of  a  piece  of 
walling,  876  feet  long,  and  5  feet  high ;  set  272|-,  which 
is  the  area  in  feet  of  a  rood  on  A,  to  876  the  length  on 
1>,  and  against  5,  the  height  on  A  are  16  roods  nearly 
on  B. 

CRANE. 

Ex.  14.  Required  the  power  of  a  crane  handle  suf¬ 
ficient  to  balance  a  weight  of  6000  lbs.  hung  on  a  pair 
of  blocks  3  pulleys  each,  the  wheel  and  roller  bearing 
such  proportion  as  2  is  to  20  in  diameter,  and  the  handle 
and  pinion  bearing  such  proportion  as  1  is  to  10  in  radius. 
Begin  first  with  the  weight  and  pulleys,  and  say  if  6  pul¬ 
leys  give  6000  lbs.,  1  pulley  or  roller  will  give  1000;  or 
set  6,  the  number  of  pulleys  on  B,  to  6000,  the  number 
of  pounds  on  A,  and  against  1  roller  on  B  is  1000  on  A, 
then  say  if  2,  the  inches  diameter  of  the  roller  or  axle 
gh  e  1000,  the  number  of  pounds  being  on  it,  or  the 
weight  over  the  6  pulleys,  equal  to  1000  lbs.  then  20 
inches,  the  diameter  of  the  wheel,  will  be  equal  to,  or 
require  100  lbs.  to  balance  it. 

Operation.  Invert  your  slide  and  set  2  the  diameter 
of  the  roller  on  C  to  1000,  the  number  of  pounds  on  A, 
and  against  20,  the  diameter  of  the  wheel  onC  is  100  lbs 


MECHANICAL  EXERCISES. 


303 


to  balance  the  whole  on  A,  then  proceed  with  the  han¬ 
dle  and  pinion,  and  say  if  1  inch,  the  radius  of  the  han¬ 
dle  has  10  lbs.  to  lift. 

Operation.  Set  1,  the  radius  of  the  pinion  on  C  to 
100,  to  the  number  of  pounds  to  lift  on  A,  and  against 
10,  the  radius  of  the  handle  on  C  is  10  lbs.  the  first 
power  applied  on  A,  the  answer  sought. 

By  this  rule  you  may  find  any  proportion  of  weight  in 
any  number  of  movements  of  any  unequal  proportion  in 
any  kind  of  mechanical  powers,  only  observe  where 
more  requires  more,  or  less  requires  less,  then  your  slide 
must  be  the  right  way  in,  as  usual,  but  when  more  re¬ 
quires  less,  and  less  requires  more,  then  your  slide  must 
be  inverted. 

Ex.  15.  Required  the  velocity  in  inches  per  minute  of 
the  crane  handle,  while  the  weight  6000  lbs.  passes  through 
a  space  of  12.6  per  minute. 

Operation.  Set  6000,  the  number  of  pounds  on  C  to 
12.6,  the  number  of  inches  and  parts  that  the  weight 
raises  on  A,  and  against  10  lbs.  the  power  applied  on  C 
is  75,  600  inches,  the  velocity  per  minute  on  A  the 
answer. 

Ex.  16.  Lever.  Suppose  a  lever  with  672  lbs.  hung  on 
the  short  arm  1  foot  from  the  fulcrum  or  prop,  required 
a  weight  to  balance,  hung  at  6  feet  from  the  fulcrum  or 
prop,  on  the  long  arm,  as  1  is  to  672,  so  is  6  to  the  num¬ 
ber  sought  or  answer;  observe,  it  must  be  worked  by 
inverse  proportion. 

Operation.  Invert  your  slide,  and  set  1  on  C  to  672 
on  A,  and  against  6  on  C  is  112  lbs.  the  answer  on  A. 

Ex.  17.  Wheel  and  Axle.  Required  a  weight  hung  on 
the  wheel  20  inches  diameter  to  balance  100  lbs.  hung  on 
the  axle  1  inch  diameter. 

Operation.  Invert  your  slide,  set  1  on  C  to  100  on  A, 
and  against  20  on  C  is  5,  the  content  on  A. 

Ex.  18.  Pulleys.  Suppose  1000"lbs.  to  be  hung  at  a 
pair  of  blocks,  consisting  of  10  pulleys,  5  loose,  and  5 
fast,  or  5  in  the  upper  and  5  in  the  lower  block,  what 
weight  should  be  hung  at  the  last  pulley  to  balance 


304 


MECHANICAL  EXERCISES. 


them?  direct  proportion,  say  as  10  pulleys  or  ropes  a»<* 
to  100  lbs.,  so  is  1  rope  or  pulley  to  10  lbs.  the  answer 
sought. 

Operation.  Set  10  on  B  to  100  on  A,  and  against  1 
on  B  is  10  the  content  on  A. 

Ex.  19.  Inclined  Plane.  Required  a  weight  hung  " 
on  the  perpendicular  height  being  12  inches  to  balance 
75  lbs.  hung  on  the  slant  height,  being  30  inches.  Direc 
proportion,  say  as  36,  slant  height  is  to  75  lbs.  so  is  12  th 
perpendicular  height  to  the  answer  25  lbs. 

Operation.  Set  30  on  B,  to  75  on  A,  and  against  12 
on  B,  is  25  the  answer  on  A. 

Ex.  20.  The  Wedge.  Required  the  power  of  a  blow 
struck  on  a  wedge,  whose  half  thickness  1  inch,  and 
length  of  one  side  25  inches,  and  resistance  250  lbs. 

Operation.  25  on  B,  to  250  on  A,  and  against  1  on  B 
is  10,  the  answer  on  A. 

Ex.  21.  The  Screw.  Required  the  resistance  or  weight 
lifted  in  pounds,  the  circumference  of  the  screw  being 
20  inches,  the  power  applied  being  100  lbs.  and  the  dis 
tance  between  two  threads  f  of  an  inch. 

Operation.  Invert  your  slide,  and  set  100  on  C,  to 
20  on  A,  and  against  75,  which  Ik  on  f-  C,  is  2050  the 
content  on  A. 

Ex.  22.  The  Engine  Beam.  Suppose  the  length  of 
the  beam  from  the  centre  to  be  6  feet  long,  and  length 
of  stroke  4  feet  long  at  the  beam  end,  required  the  length 
of  stroke,  the  same  beam  is  making  at  11,  3  feet  and  4] 
feet  from  the  centre,  or  any  other  length  of  stroke  within 
the  same  dimensions. 

Operation.  Set  4,  the  length  of  stroke  on  B  to  0,  the 
length  of  the  beam  from  the  centre  on  A,  and  against 
11,  3  and  41  feet  on  A  is  1,  2,  and  3  feet,  the  content  on 
B,  or  any  other  length  that  might  be  wanted  within  the 
same  dimension. 

Ex.  23.  Suppose  the  piston  of  a  steam  engine  to  travel 
220  feet  per  minute,  and  the  length  of  stroke  up  and 
down  to  be  8  feet,  what  is  the  number  of  strokes  per 
minute. 


MECHANICAL  EXERCISES.  305 

Operation.  Set  8  on  B  to  1  on  unity  on  A,  and  against 
220  on  B  is  274,  the  content  on  A. 

Ex.  24.  Suppose  a  piston  to  travel  220  feet  per  min¬ 
ute,  and  the  number  of  strokes  to  be  27^  per  minute, 
what  is  the  length  of  one  stroke  up  and  down. 

Operation.  Set  27^  on  A  to  220  on  B,  against  1  on 
A,  being  8  feet,  the  length  of  stroke  on  B.  * 

Ex.  25.  Required,  the  number  of  feet  a  piston  travels 
in  a  minute,  length  of  stroke  being  8  feet,  and  numbei  of 
strokes  being  27^. 

Operation.  >Set  1  on  A  to  8  on  B,  and  against  27^  on 
A,  is  220  on  B. 

Ex.  26.  If  a  pendulum  39.2  inches  long,  make  60  vi¬ 
brations  per  minute,  what  will  one  of  12  inches  long 
make. 

Operation.  Invert  your  slide,  and  set  39.2  on  B  to  60 
on  D,  and  against  12  on  B,  is  109,  the  content  on  D. 

Ex.  27.  Required,  the  number  of  feet  a  stone  will  fall 
in  3  seconds,  supposing  it  to  fall  16  feet  in  the  first 
second. 

Operation.  Set  1  on  D  to  16  on  C,  and  against  3  on 
D,  is  144  feet,  the  content  on  C. 

Ex.  28.  Required,  the  circumference  of  a  wheel,  the 
diameter  being  20  inches. 

Operation.  Set  1  on  B  to  -3.14  on  A,  and  against  20 
on  B,  is  63,  the  content  on  A. 

Ex.  29.  Required,  the  diameter  of  a  wheel,  the  cir¬ 
cumference  being  63  inches. 

Operation.  Set  3.14,  which  is  the  circumference  of 
1  inch  on  A,  to  1,  the  diameter  on  B,  and  against  63,  the 
circumference  on  A  is  20,  the  diameter  on  B.  By  this 
rule,  you  find  the  pitch  of  all  wheels  nearly  by  setting 
the  pitch  of  the  cog  on  B  to  3.14  on  A,  and  against  any 
diameter  on  B,  is  the  number  of  cogs  on  A,  or  against 
any  number  of  cogs  on  A,  is  the  diameter  on  B. 

Ex.  30.  Suppose  a  drum  upon  one  shaft  20  inches 
diameter,  to  make  30  revolutions,  which  is  turned  by  a 
first  drum ;  then  required  the  diameter  of  the  last  drum, 
that  makes  150  revolutions. 

26  * 


U 


306 


MECHANICAL  EXERCISES. 


Operation.  Invert  your  slide,  and  set  30,  the  revolu¬ 
tions  of  the  first  drum  on  A  to  20,  the  diameter  of  the 
first  drum  in  C,  and  against  150,  the  revolution  of  the 
ast  drum  on  A  is  4  inches,  the  diameter  of  the  last  drum 
on  C.  By  this  rule,  you  will  find  the  revolution  or  diam¬ 
eter  of  any  different  speed  of  any  number  of  drums  of  an 
unequal  proportion ;  for,  as  the  revolutions  on  A  are  to 
the  diameter  on  C,  so  is  the  diameter  to  the  revolutions 
on  A,  or  number  sought.  Observe,  the  slide  must  alway 
be  inverted  in  these  operations. 

Ex.  31.  Tiling  and  Slating.  Required  the  number 
of  Squares  contained  in  a  piece  of  tiling  or  slating  40 
feet  long  by  15  wide. 

Operation.  Set  100  the  number  of  feet  in  a  square 
on  A  to  40  the  length  on  B,  and  against  15,  the  width  on 
A  is  6,  the  content  on  B. 

Ex.  32.  Required  the  number  of  roods  contained  in 
the  above  dimensions. 

Operation.  Set  63,  the  number  of  feet  in  a  rood  on 
A  to  40,  the  length  on  B,  against  15  on  A  is  9^  roods 
the  content  on  B. 

Ex.  33.  Required  the  number  of  tiles  sufficient  to 
cover  the  above  dimensions. 

Operation.  Set  1  on  A  to  101^,  the  tiles  in  a  rood 
on  B,  and  against  9^  the  roods  on  A  is  965,  the  number 
of  tiles  required  on  B. 

Ex.  34.  Painters'  Work.  Required  the  number  of 
yards  contained  in  a  fence  of  70  feet  long,  by  10i  feet 
high. 

Operation.  Set  9,  the  number  of  feet  in  a  yard  on 
A  to  70  the  length  on  B,  and  against  lOf  on  A  is  81f 
the  contents  on  B. 

Ex.  35.  Glaziers'  Work.  Required  the  number  of 
feet  contained  in  a  window  60  in.  high,  and  50  wide. 

Operation.  Set  144,  the  number  of  superficial  inch¬ 
es  in  a  foot  on  A  to  60,  the  length  on  B,  and  against  50, 
the  width  on  A  is  nearly  21.0  feet,  the  content  on  B,  or 
call  it  5  feet  high,  and  set  12  on  A  to  5  on  B,  and 
against  50  on  A  is  nearly  21.0  feet,  the  same  as  above 
on  B 


MECHANICAL  EXERCISES. 


307 

Lx.  36  Plasterers’  Work.  Required  the  number  of 
yards  contained  in  a  piece  of  plastering,  42  feet  long  by 
84  feet  high. 

Operation.  Set  9  on  A  to  12,  the  length  on  B,  and 
against  8i  feet  high  is  39|-  yards  nearly  on  B. 

Ex.  37.  Pavers’  Work.  Required  the  number  of 
yards  contained  in  a  piece  of  paving  lGi  feet  long  by 
13f  wide. 

Operation.  Set  9  on  A  to  164,  the  length  on  B,  an 
against  13|^  on  A,  are  35  yards,  the  content  on  B. 

Ex.  38.  Required  the  number  of  bricks  sufficient  for 
the  above  25  yards,  admitting  the  size  of  bricks  to  be  9 
by  4|  inches,  and  a  superficial  yard  to  contain  32  bricks. 

Operation.  Set  1  on  A  to  32  on  B,  and  against  25  on 
A  are  800  bricks,  the  content  on  B. 

Ex.  39.  Digging.  Required  the  number  of  solid  yards 
contained  in  a  piece  of  digging  15  feet  long,  12  feet  wide 
and  2  feet  deep ;  first  find  the  mean  proportion  by  setting 
15  on  D  to  15  on  C,  and  against  12  on  C  is  13,  45,  the 
square  on  D. 

Operation.  Set  9  the  depth  on  B  to  17,  the  common 
divisor,  on  A,  and  against  13,  45  on  D,  are  60  yards,  the 
content  on  C. 

Ex.  40.  Timber  Measure.  Required  the  number  of 
cubic  feet  contained  in  a  piece  of  timber  22  feet  long,  and 
18  inches  {  girt. 

Operation.  Set  22,  the  length  on  B  to  9  the  common 
divisor  on  A,  and  against  the  \  girt  on  D  are  49|-  feet, 
the  content  on  C. 

Ex.  41.  Required  the  product  of  2f  inches,  multi¬ 
plied  by  2f  inches. 

Operation.  Set  1  on  A  to  2|  on  B,  and  against  2f  or. 
A  is  7.6,  the  content  on  B. 

Ex.  42.  Required  the  number  of  Horse-power  of  a 
double  powered  Patent  Steam  Engine,  the  diameter  of 
the  cylinder  being  24  inches. 

Operation.  Set  5  on  B  to  9  on  A,  and  against  24  on 
D  is  20  the  content  on  C;  observe,  when  the  slide  stands 
here,  it  is  a  table  of  diameters  and  horses’-power,  D  being 
a  line  of  diameters,  and  C  being  a  line  of  horses’-power 


308 


MECHANICAL  EXERCISES. 


Ex.  43.  Required  (he  side  of  a  square  in"  inches 
iqual  in  area  to  a  right  angle  triangle,  whose  base  is  126 
nches,  and  perpendicular  height  94  inches. 

Operation.  Set  47,  which  is  half  the  perpendicular 
an  C  to  47  the  same  on  D,  and  against  126  on  C  is  76.9 
the  content  on  D;  observe,  taking  half  the  perpendicular 
is  the  common  rule*  in  all  triangles  to  find  the  area. 

Ex.  44.  Required  the  side  of  a  square  in  feet,  equal 
in  area  to  a  common  triangle,  whose  base  is  48  feet,  and 
perpendicular  height  24  feet. 

Operation.  Set  12,  which  is  half  the  perpendicular 
on  C  to  12  the  same  on  D,  and  against  48  on  C  is  24,  the 
answer  on  D. 

Ex.  45.  Required,  the  weight  of  a  hay-stack,  admit¬ 
ting  1  solid  yard,  or  27  solid  feet,  to  1  cvvt.  1  qr.  0  lb., 
and  the  stack  to  measure  30  feet  long,  12  feet  wide,  and 
10  feet  high,  up  to  the  hips,  or  eaves.  In  this  case,  it  will 
be  necessary  to  take  the  length  and  width  about  5  feet 
high,  that  is,  about  the  middle,  calling  this  the  mean 
proportion,  which  will  be  sufficiently  true  in  cases  of 
this  kind. 

Operation.  The  first  thing  is  to  find  the  square  of  it, 
which  is  necessary,  in  all  unequal  dimensions,  before  the 
question  can  be  stated  :  this  is  found. by  setting  30,  the 
feet  long,  on  30,  the  same  on  D,  and  against  12,  the  feet 
wide  on  C,  are  19,  the  feet  square  on  i)  nearly,  then  set 
10,  the  feet  high  on  13,  to  this  common  number  or  divisor, 
136  on  A,  and  against  19,  the  feet  square  on  D,  is  1 67 
cwt.  0  qr.  0  lb.,  the  content  on  C. 

Ex.  46.  Required,  the  content  of  the  top  of  the  stack 
(that  is,  that  part  above  the  hips  or  eaves,  which  con¬ 
tains  the  roof,  &c.,)  its  length  being  30  feet,  width  being 
12,  and  perpendicular  height  being  10  feet. 

Operation.  Set  5,  which  is  half  the  perpendicular  on 
B,  that  is,  the  depth  to  that  common  number  or  divisor 
136,  as  above,  and  against  19,  the  square  on  D,  as  in  ex¬ 
ample  above,  is  83  cwt.  1  qr.,  the  content  on  C.  Now, 
the  body  of  the  stack  being  167  cwt.  0  qr.  0  lb.,  which 
being  added  to  83  cwt.  1  qr.  0  lb.,  makes  the  whole  2 50 
cvrt.  1  qr.,  the  answer. 


MECHANICS. 


The  science  of  mechanics  has  been  very  concisely  de¬ 
fined  the  geometry  of  motion.  It  is  divided,  by  Sir  Isaac 
Newton,  into  the  two  branches  of  practical  and  rational 
mechanics.  Practical  mechanics  treat  of  the  six  mechani¬ 
cal  powers,  of  one  or  more  of  which  every  machine  is 
composed ;  and  rational  mechanics  comprehends  the 
whole  theory  of  motion,  shows  how  to  determine  the  mo¬ 
tions  produced  by  given  powers  or  forces,  and,  conversely, 
when  the  phenomena  of  the  motions  are  given,  how  to 
trace  the  power  of  forces  from  which  they  arise. 

To  enter  into  a  full  detail  of  mechanics,  would  swell 
this  volume  beyond  its  intended  limits;  and,  having 
dwelt  somewhat  at  large  on  mechanical  exercises,  under 
this  head,  we  shall  only  add  an  Abstract  of  Mechanics. 

ABSTRACT  OF  MECHANICS. 

OF  MATTER. 

1.  Every  portion  of  matter  is  possessed  of  the  follow¬ 
ing  properties,  viz.  solidity,  extension,  divisibility,  mobility, 
inertia,  attraction,  and  repulsion. 

2.  Solidity  is  that  property  by  which  two  bodies  can¬ 
not  occupy  the  same  place  at  the  same  time.  It  is  some¬ 
times  called  the  impenetrability  of  matter. 

3.  The  extension ,  like  the  solidity  of  matter,  is  proved 
by  the  impossibility  of  two  bodies  co-existing  in  the  same 
place. 

4.  Divisibility  is  that  property  by  which  bodies  are 
capable  of  being  divided  into  parts  removeable  from  each 
other. 

5.  Mobility  expresses  the  capacity  of  matter  to  be 
moved  from  one  position  or  part  of  space  to  another. 

(309) 


310  ABSTRACT  OF  MECHANICS. 

0.  Inertia  is  the  term  which  designates  the  passiveness 
of  matter,  which,  if  at  rest,  will  for  ever  remain  in  that 
state,  until  compelled  by  some  cause  to  move ;  and,  on 
the  contrary,  if  in  motion,  that  motion  will  not  cease,  or 
abate,  or  change  its  direction,  unless  the  body  be  resisted. 

SPACE. 

1.  Space  is  cither  absolute  or  relative. 

2.  Absolute  space  is  merely  extension,  illimitable,  im¬ 
moveable,  and  without  parts ;  yet,  for  the  convenience 
of  language,  it  is  usually  spoken  of  as  if  it  had  parts. 
Hence  the  expression, 

3.  Relative  space,  which  signifies  that  part  of  absolute 
space  which  is  occupied  by  any  body,  as  compared  with 
any  part  occupied  by  another  body. 

ATTRACTION. 

1.  Attraction  denotes  the  property  which  bodies  have 
to  approach  each  other. 

2.  There  are  five  kinds  of  attraction,  the  attraction 
of  cohesion,  of  gravitation,  of  electricity,  of  magnetism, 
and  chemical  attraction. 

3.  The  attraction  of  cohesion  is  exerted  only  at  very 
small  distances. 

4.  The  strength  of  the  attraction  of  cohesion  being 
different  in  different  kinds  of  matter,  is  supposed  to  be 
the  cause  of  the  relative  degrees  of  hardness  of  different 
bodies. 

5.  Capillary  attraction  is  only  a  particular  modification 
or  branch  of  the  attraction  of  cohesion. 

0.  The  attraction  of  gravitation  is  exerted  by  every 
particle  of  matter  on  every  other  particle  at  all  distances, 
but  bv  no  means  with  equal  intensity  at  all  distances. 

7.  Gravitation  decreases  from  the  surface  of  the  earth 
upwards  as  the  square  of  the  distance  increases  ;  but 
from  the  surface  of  the  earth  doivn  wards,  it  decreases 
only  in  a  direct  ratio  to  the  distance  from  the  centre. 


311 


ABSTRACT  OP  MECHANICS. 

REPULSION. 

1.  Repulsion  is  that  property  in  bodies,  whereby,  if 
Uiey  are  placed  just  beyond  the  sphere  of  each  other’s 
attraction  of  cohesion,  they  mutually  fly  from  each  other. 

•  Oil  refuses  to  mix  with  water,  from  the  repulsion 
between  the  particles  of  the  two  substances;  and  from 
the  same  cause,  a  needle  gently  laid  upon  water  will  swim. 

MOTION. 

1.  Absolute  motion  is  the  actual  motion  that  bodies 
have,  considered  indepemv  ntly  of  each  other,  and  only 
with  regard  to  the  parts  o  space. 

2.  Relative  motion  is  tl  j  degree  and  direction  of  the 
motion  of  one  body,  when  impared  with  that  of  another. 

.  Accelerated,  motion  i.  when  the  velocity  continually 
increases.  J 

4.  Retarded  motion  is  when  the  velocity  continually 
decreases ;  and  the  motion  is  said  to  be  uniformly  re¬ 
tarded,  when  it  decreases  equally  in  equal  times. 

5.  The  velocity  of  uniform  motion  is  estimated  by  the 
time  employed  in  moving  over  a  certain  space ;  or,  which 
amounts  to  the  same  thing,  by  the  space  moved  over  in  a 
certain  time. 

6.  To  ascertain  the  velocity,  divide  the  space  run  over 
by  the  time. 

7.  To  ascertain  the  space  run  over,  multiply  the  veloci¬ 
ty  by  the  time. 

8.  In  accelerated  motion,  the  space  run  over  is  as  the 
square  of  the  time,  instead  of  being  directly  as  the  time 
as  in  uniform  motion. 

9.  A  body  acted  upon  by  only  one  force,  will  always 

move  in  a  straight  line.  J 

10.  Bodies  acted  upon  by  two  single  impulses,  whether 
equal  or  unequal,  will  also  describe  a  right  line. 

11.  But  when  a  body  is  acted  upon  by  one  uniform 
orce,  or  single  impulse,  and  another  accelerated  or  re¬ 
al  e  orce,  the  two  forces  will  cause  it  to  describe  a 

curve- 


312  ABSTRACT  OF  MECHANICS. 

12.  The  curve  described  by  a  body  projected  from  the 
earth,  and  drawn  down  by  the  action  of  gravity,  would 
in  an  unresisting  medium,  be  that  of  a  parabola ;  bu 
from  the  resistance  of  the  air,  which,  when  the  velocity 
is  very  great,  will  often  amount  to  one  hundred  times 
the  weight  of  the  projectile,  the  curve  really  described 
approaches  more  nearly  to  that  of  a  hyperbola. 

13.  The  momentum  of  a  body  is  the  force  with  which 
it  moves,  and  is  in  proportion  to  the  weight,  or  quantity 
of  matter,  multiplied  into  its  velocity. 

14.  The  actions  of  bodies  on  each  other  are  always 
equal,  and  exert  in  opposite  directions ;  so  that  any  body 
acting  upon  another,  loses  as  much  force  as  it  commu 
nicates. 

CENTRAL  FORCES. 

1.  The  central  forces  are  the  centrifugal  and  the 
centripetal  forces. 

2.  The  centrifugal  force  is  the  tendency  which  bodies 
that  revolve  round  a  centre,  have  to  fly  from  it  in  a 
tangent  to  the  curve  they  move  in,  as  a  stone  from  a 
sling. 

The  centripetal  force  is  that  which  prevents  a  body 
from  flying  off,  by  impelling  it  towards  the  centre,  as  the 
attraction  of  gravitation. 

CENTRE  OF  GRAVITY. 

1.  The  centre  of  gravity  is  that  point  in  a  body  about 
which  all  its  parts  exactly  balance  each  other  in  every 
position. 

2.  A  vertical  line  passing  through  the  centre  of  gra¬ 
vity  of  a  body,  is  called  the  line  of  direction. 

3.  When  the  line  of  direction  falls  within  the  base  of 
a  body,  that  body  cannot  descend ;  but  if  it  falls  without 
the  base,  the  bodv  will  fall. 

THE  LEVER. 

1.  There  are  three  kinds  of  levers,  the  difference 
between  which  is  constituted  by  the  difference  in  the 


ABSTRACT  OF  MECHANICS.  '  313 

situation  of  the  fulcrum,  and  the  power  with  respect  to 
each  other.  In  the  first  kind  of  lever,  the  fulcrum  is 
placed  between  the  power  and  the  weight.  In  the  second 
kind  ol  lever,  the  fulcrum  is  at  one  end,  the  power  at 
the  other,  and  the  weight  between  them.  In  the  third 

kind  of  lever,  the  power  is  applied  between  the  fulcrum 
and  the  weight. 

2.  In  all  these  levers,  the  power  is  to  the  weight,  as 
the  distance  of  the  weight  from  the  fulcrum  is  To  that 
of  the  power  from  the  fulcrum. 

3.  A  bent  or  hammer  lever,  differs  only  in  the  form 
from  a  lever  of  the  first  kind. 

4.  Scissors,  pincers,  snuffers,  and  the  common  iron 
screw,  are  all  levers  of  the  first  kind. 

o.  I  he  strutera  or  Roman  steel-yard,  is  a  lever  of  the 
first  kind,  with  a  moveable  weight. 

G.  A  balance  is  also  a  lever  of  the  first  kind  with 
equal  arms ;  a  perfect  balance  should  combine  the  fol¬ 
lowing  requisites.  1.  The  arms  of  the  beam  should  be 
.  exactly  equal,  both  as  to  weight  and  length,  and  should 
at  the  same  time  be  as  long  as  possible,  relatively  to 
their  thickness.  2.  The  points  from  which  the  scales  are 
suspended,  should  be  in  a  right  line,  passing  through  the 
centre  of  gravity  of  the  beam.  3.  The  fulcrum  ought 
to  be  a  little  higher  than  the  centre  of  gravity.  4.  The 
axis  of  motion  should  be  formed  with  an  edge  like  a 
knife,  and,  with  the  rings  and  other  bearing  parts,  should 
be  very  hard  and  smooth.  5.  The  pivots,  which  form 
the  axis  of  motion,  should  be  in  a  straight  line,  and  at 
right  angles  to  the  beam. 

7.  The  best  balances  are  not  calculated  to  determine 
weights  with  certainty  to  more  than  five  places  of 
figures. 

8.  The  oars  and  rudders  of  vessels  are  levers  of  the 
second  order;  a  pair  of  bellows,  nut-crackers,  &c.  are 
composed  of  two  levers  of  the  same  kind. 

9.  The  third  kind  of  lever  is  used  as  little  as  possible, 
on  account  of  the  disadvantage  to  the  moving  power,  the 
intensity  of  which  must  always  exceed  the  resistance 

27 


314  ABSTRACT  OF  MECHANICS. 

yet  in  some  enses  this  disadvantage  is  over-balanced  ny 
the  quickness  of  its  operations,  and  the  small  compass  in 
which  it  is  exerted ;  hence  its  fitness  for  the  bones  of  the 
arm,  and  the  limbs  of  animals  generally. 

10.  In  compound  levers,  the  power  is  to  the  weight,  in 
a  ratio  compounded  of  the  several  ratios  which  those 
powers  that  can  sustain  the  weight  by  the  half  of  each 
lever,  when  used  singly  and  apart  from  the  rest,  have  to 
the  weight. 

THE  PULLEY. 

1.  Pulleys  are  of  two  kinds,  fixed  and  moveable. 

2.  The  fixed  pulley  only  turns  upon  its  axis,  and  allords 
no  mechanical  advantage;  therefore,  when  the  powci 
and  the  weight  are  equal,  they  balance  each  other.  It 
is  used  for  the  convenience  of  changing  the  direction  of  a 
motion. 

3.  The  moveable  pulley  not  only  turns  upon  its  axis,  bu* 
rises  and  falls  with  the  weight. 

4.  Every  moveable  pulley  may  be  considered  as  hang 
ing  by  two  ropes  equally  stretched,  and  which,  conse¬ 
quently,  being  equal  portions  of  the  weight,  therefore 
each  pulley  of  this  sort  doubles  the  power. 

5.  A  pulley  of  one  spiral  groove  upon  a  truncated  cone 
as  the  fusee  of  a  watch,  is  calculated  to  maintain  a  con¬ 
stant  equilibrium  or  relation  between  two  powers,  the 
relative  forces  of  which  are  continually  changing. 

WHEEL  AND  AXLE. 

1.  The  power  must  be  to  the  weight,  in  order  to  pro¬ 
duce  an  equilibrium,  as  the  circumference  of  the  wheel  is 
to  the  circumference  of  the  axle. 

2.  As  the  diameters  of  different  circles  bear  the  same 
proportion  to  each  other  that  their  respective  circum¬ 
ferences  do,  the  power  is  also  to  the  weight  as  the  diam¬ 
eter  of  the  wheel  to  the  diameter  of  the  axle. 

3.  If  one  wheel  move  another  of  equal  circumference 
no  power  will  be  gained,  as  they  will  both  move  equally 
fast. 


ABSTRACT  OF  MECHANICS.  315 

4.  But  if  one  wheel  move  another  of  different  diame¬ 
ter,  whether  larger  or  smaller,  the  velocities  with  which 
they  move  will  be  inversely  as  their  diameters,  circum¬ 
ferences,  or  number  of  teeth. 

5.  The  wheel  and  axle  may  be  considered  as  a  per¬ 
petual  lever,  from  the  constant  renewal  of  the  points  of 
suspension  and  resistance.  The  fulcrum  is  the  centre  of 
the  axis,  the  longer  arm  is  the  radius  of  the  wheel,  and 
the  shorter  arm  the  radius  of  the  axis. 

6.  The  crane,  and  many  other  machines,  of  the  first 
consequence,  are  composed  principally  of  the  wheel  and 
axle. 

THE  INCLINED  PLANE. 

1.  The  power  and  the  weight  balance  each  other, 
when  the  former  is  to  the  latter  as  the  height  of  the 
plane  to  its  length 

2.  In  estimating  the  draught  of  a  wagon,  or  other 
vehicle,  up-hill,  the  draught  on  the  level  must  be  added; 
so  that,  if  the  hill  rises  one  foot  in  four,  one  fourth  part 
of  the  weight  must  be  added  to  the  draught  on  level 
ground. 

THE  WEDGE. 

1.  When  the  resistance  acts  perpendicularly  to  the 
sides,  that  is,  when  the  wedge  does  not  cleave  at  any 
distance,  there  is  an  equilibrium  between  the  resistance 
and  the  power,  when  the  latter  is  to  the  former  as  half 
the  thickness  of  the  back  of  the  wredge  is  to  th£  length 
of  one  of  its  sides. 

2.  When  the  resistance  on  each  side  acts  parallel  to 
the  back,  that  is,  when  the  wedge  cleaves  at  some  dis¬ 
tance,  the  power  is  to  the  resistance  as  the  whole  length 
of  the  back  to  double  its  perpendicular  height. 

3.  The  thinner  the  wedge,  the  greater  its  power. 

4.  The  further  a  wedge  is  driven  into  anv  material, 
the  greater  also  is  its  power,  the  sides  of  the  cleft  afford¬ 
ing  it  the  advantage  of  operating  upon  two  levers. 

5.  Axes,  spades,  chisels,  knives,  and  all  instruments 


ABSTRACT  OF  MECHANICS. 


310 

which  begin  with  edges'  or  points,  and  grow  graduallj 
thicker,  act  on  the  principle  of  the  wedge. 

THE  SCREW. 

1.  The  screw  is  an  inclined  plane  encompassing  the 
cylinder. 

2.  It  is  generally  used  with  a  lever ;  and  the  power  is 
to  the  weight,  as  the  distance  from  one  thread  or  spiral 
to  another  is  to  the  circumference  of  the  circle  described 
by  the  power. 

3.  The  friction  of  the  screw  is  very  great,  a  circum¬ 
stance  that  occasions  this  machine  to  sustain  a  weight  or 
press  upon  a  body,  after  the  power  by  which  it  was 
impelled  is  removed. 

4.  A  screw  cut  on  an  axle  to  serve  as  a  pinion,  is 
called  an  endless  screw. 

5.  The  endless  screw  is  very  useful,  either  in  converting 
a  very  rapid  motion  into  a  slow  one,  or  vice  versa,  as  for 
each  of  its  revolutions  the  wheel  moves  but  one-tenth. 

COMPOUND  MACHINES. 

1.  In  all  machines,  simple  as  well. as  compound,  what 
is  gained  in  power  is  lost  in  time ;  but  the  loss  of  time  is 
.compensated  by  convenience. 

2.  The  mechanical  power  of  an  engine  may  be  known 
by  measuring  the  space  described  in  the  same  time  by 
the  power  and  the  resistance  or  weight ;  or  by  multiply¬ 
ing  into  each  other  the  several  proportions  subsisting 
between  the  power  and  the  weight,  in  every  simple  me¬ 
chanical  ‘power  of  which  it  is  composed. 

3.  The  power  of  a  machine  is  not  altered  by  varying 
the  siz~  of  the  wheels,  provided  the  proportion  produced 
by  the  multiplication  of  the  power  of  t lie  several  parts 
remains  the  same. 

4.  In  constructing  machines,  simplicity  of  parts  and 
uniformity  of  motion  should  be  particularly  studied. 

5.  The  teeth  of  wheels  should  always  he  made  as 
numerous  as  possible ;  and  when  great  strength  is  rc- 
quired,  it  should  be  obtained  by  increasing  the  width  or 

hickness  of  the  wheel. 


ABSTRACT  OF  MECHANICS.  317 

6.  The  use  of  the  crank  is  one  of  the  best  modes  of 
converting  a  reciprocating  into  a  rotatory  motion,  and 
vice  versa.. 

FLY-WHEELS. 

L  A  fly-wheel  is  a  reservoir  of  power,  and  is  employed 
to  equalize  the  motion  of  a  machine. 

2.  This  equalization  of  the  motion  is  the  only  source 
of  the  advantage  of  a  fly,  which  can  impart  no  power  it 
has  not  received. 

3.  When  a  fly  is  used  merely  as  a  regulator,  it  should 
be  near  the  first  mover  ;  if  intended  to  accumulate  force 
in  the  working  point,  it  should  not  be  separated  far  from 
that  point. 

FRICTION.  „ 

1.  Friction  is  occasioned  by  the  roughness  and  cohe¬ 
sion  of  bodies. 

2.  It  is  in  general  equal  to  between  one-half  and  one- 

fourth  of  the  weight  or  force  with  which  bodies  are 
pressed  together.  ' 

3.  It  is  increased  .in  a  small  degree  by  an  increase  of 
the  surfaces  in  contact. 

4.  It  is  increased  to  an  extraordinary  degree,  by  pro-* 
longing  the  time  of  contact.  ' 

5.  Two  metals  of  the  same  kind  have  more  friction 
than  two  different  metals. 

6.  Steel  and  brass  are  the  two  metals  which  have  the 
least  friction  upon  each  other. 

7.  The  general  rule  for  lessening  friction  consists  in 
substituting  the  roiling  for  the  sliding  motion. 

MEN  AND  HORSES,  CONSIDERED  AS  FIRST 

MOVERS. 

1.  In  turning  a  wrench,  a  man  exerts  his  strength  in 
different  proportions  at  different  parts  of  the  circle.  The 
force  is,  when  he  pulls  the  handle  up  from  the  height  of 
his  knee ;  and  the  least  when  he  thrusts  from  him  hori< 
zon  tally. 

27* 


ABSTRACT  OF  MECHANICS. 


318 

2.  When  two  handles  are  used  to  an  axle,  one  at  each 
extremity,  they  should  be  fixed  at  right'  angles  to  each 
other. 

3.  The  art  of  carrying  large  burdens,  consists  in  keep¬ 
ing  the  column  of  the  body  as  directly  under  the  weight 
and  as  upright  as  possible. 

4.  The  horse  exerts  his  force  to  the  greatest  advan¬ 
tage  in  drawing  or  carrying  up  a  hill. 

5.  The  force  with  which  a  horse  works,  is  compounded 
of  his  weight  and  muscular  strength. 

G.  The  walk  of  a  horse  working  in  a  mill  should  never 
be  less  than  forty  feet  in  diameter. 

7.  A  horse  exerts  most  strength  when  drawing  upon  a 
plane. 

MILL-WORK. 

1.  Water-wheels  are  of  three  kinds;  viz.  undershot- 
wheels,  breast-wheels,  and  overshot-wheels.  The  powers 
necessary  to  produce  the  same  effect  on  each  of  these 
must  be  to  each  as  the  numbers  2.4,  1.75,  and  1. 

2.  The  undershot-wheel  is  used  only  when  a  fall-water 
cannot  be  obtained. 

3.  A  water-wheel  twice  as  broad  as  another  has  more 
•  than  double  the  force. 

4.  An  axis,  furnished  with  a  very  oblique  spiral,  and 
placed  in  the  direction  of  a  stream,  may  be  rendered  a 
powerful  first-mover,  adapted  to  a  deep  and  slow  current 

5.  A  mill-stone  should  make  120  revolutions  in  a 
minute. 

6.  Bevelled-wheels  are  much  used  for  changing  the 
direction  of  motion  in  wheel  work. 

7.  Hooke’s  universal  joint  is  sometimes  used  with  ad 
vantage  for  the  same  purpose. 

8.  The  teeth  of  wheels  should  never,  if  it  can  be 
avoided,  act  upon  each  other  before  they  arrive  at  the 
line  joining  the  centres. 

9.  To  ensure  a  uniformity  of  pressure  and  velocity  in 
the  action  of  one  wheel  upon  another,  the  teeth  should 
be  formed  into  epicycloides,  or  into  involutes,  of  the  cir- 


ABSTRACT  OF  MECHANICS. 


319 

cumferences  of  the  respective  wheels ;  or  if  the  teeth  of 
one  wheel  be  either  circular  or  triangular,  the  teeth  of 
he  same  wheel  should  have  a  hgure  compounded  of  an 
epicycloid,  and  that  of  the  figure  of  the  first  wheel. 

10.  The  object  of  thus  forming  the  teeth  is,  that  they 
may  not  slide ,  but  roll  upon  each  other ;  by  which  means, 
the  friction  is  almost  annihilated. 

11.  It  is  a  great  improvement  in  machinery,  where 
trundles  are  employed  with  cylindrical  staves,  to  make 
these  staves  moveable  on  their  axis. 

12.  A  heavy  mill-stone  requires  very  little  more  powrer 
than  a  light  one ;  but  it  performs  much  more  work,  and 
more  effectually  equalizes  the 'motion,  like  a  heavy  fly. 

13.  The  corn  as  it  is  ground,  is  thrown  out  between 
the  mill-stones,  by  the  centrifugal  force  it  has  acquired. 

14.  The  manual  labour  of  putting  the  ground  corn  into 
sacks,  in  order  to  raise  it  to  the  top  of  a  mill-house,  may 
be  obviated  by  the  use  of  a  chain  of  buckets  wrought 
by  machinery. 

WHEEL  CARRIAGES. 

1.  A  horse  draws  with  the  greatest  advantage,  when 
the  line  of  traction  or  draught  is  inclined  upwards,  so  as 
to  make  an  angle  of  about  15  degrees  with  the  horizon¬ 
tal  plane. 

2.  By  this  inclination,  the  line  of  traction  is  set  at 
right  angles  to  the  shape  of  the  horses’  shoulders,  all 
parts-  of  which  are,  therefore,  equally  pressed  by  the 
collar. 

3.  Single  horses  are  preferable  to  teams,  because  in  a 
team,  all  but  the  shaft  horse  draw  horizontally,  and  con¬ 
sequently  to  disadvantage. 

4.  A  horse,  when  part  of  the  weight  presses  on  his 
back,  will  draw  a  weight  to  which  he  w'ould  otherwise 
be  incompetent. 

5.  The  fore-wheels  of  carriages  are  less  than  the  hind 
wheels,  for  the  convenience  of  turning  in  a  smaller  com¬ 
pass. 

6.  In  ascending,  high  wheels  facilitate  the  draught,  in 


320 


ABSTRACT  OF  MECHANICS. 


proportion  to  the  squares  of  their  diameters;  but  in 
descending,  they  press  in  the  same  proportion. 

7.  In  descending,  the  body  of  a  cart  may  be  advan¬ 
tageously  thrown  backwards,  so  that  the  bottom  of  it 
will  be  horizontal,  while  the  shafts  incline  downwards. 

8.  In  loading  four-wheeled  carriages,  the  greatest 
weight  should  be  laid  upon  the  large  wheels. 

9.  Dished  wheels  are  better  calculated  than  any  other 
to  sustain  the  jolts  and  unavoidable  inequalities  of  pres¬ 
sure  arising  from  the  roughness  of  roads. 

10.  The  extremities  of  the  axles  should  be  in  the  same 
horizontal  plane,  and  the  wheels  should  be  placed  on 
them  at  right  angles. 

11.  Broad  cylindrical  wheels  smooth  and  harden  a 
road,  while  narrow  ones  cut  it  into  furrows,  and  conical 
ones  grind  the  hardest  stones  to  powder. 

CLOCK-WORK. 

1.  To  ascertain  the  number  of  revolutions  which  a 
pinion  makes,  for  one  of  the  wheels  working  in  it,  divide 
the  number  of  its  leaves  by  the  number  of  teeth  of  the 
wheel,  and  the  answer  is  obtained. 

2.  By  increasing  the  number  of  teeth  in  the  wheels : 
by  diminishing  the  number  of  leaves  in  the  pinions ;  by 
increasing  the  length  of  the  cord  that  suspends  the 
weight ;  and  lastly,  by  adding  to  the  number  of  wheels 
and  pinions,  a  clock  may  be  made  to  go  any  length  of 
time,  as  a  month,  or  a  year,  without  winding  up.  • 

3.  The  inconvenience  of  taking  up  more  room,  but 
principally  the  increase  of  friction  which  would  be  in 
troduced,  are  the  causes  of  its  being  inexpedient  to 
make  a  clock  go  beyond  eight  days.  - 

4.  Clocks  intended  to  keep  exact  time,  are  contrived 
to  go  whilst  winding  up. 

5.  Clocks  which  have  pendulums  vibrating  half  se¬ 
conds,  are  frequently  moved  by  a  spring  instead  of  a 
weight. 

G.  A  spring  is  strongest  when  it  is  first  wound  up,  auJ 
gradually  decreases  in  strength  till  the  movement  stops 


ABSTRACT  OF  MECHANICS. 


321 

it  is  therefore  contrived  to  draw  the  chain  over  a  conical 
barrel,  so  that  the  lever  at  which  it  pulls  is  lengthened 
as  it  grows  weaker,  by  which  means  its  effects  are 
equalized. 

7.  The  plates  of  clock-makers’  engines  may  be  quick¬ 
ly  divided  into  odd  numbers,  by  subtracting  from  the  odd 
number  so  much  as  will  leave  an  even  number  of  easy 
subdivision  ;  then  calculating  the  number  of  degrees  con¬ 
tained  in  the  parts  subtracted,  and  setting  them  off  on 
the  circumference  of  the  circle  from  a  sector. 

8.  The  geometrical  radius  of  wheels,  when  the  teeth 
are  epicycloidai,  is  less  than  the  acting  diameter,  by 
about  fths  of  the  breadth  of  a  teeth  or  measure. 

9.  I  he  relative  size  of  a  pinion  must  be  less  for  a 
small  wheel  than  for  a  large  one,  and  also  smaller  when 
driven  than  when  it  is  the  driver. 

PENDULUMS. 

1.  All  vibrations  of  the  same  pendulum,  whether 
great  or  small,  if  cycloidal,  are  performed  in  equal  times. 

2.  The  longer  a  pendulum,  the  slower  are  its  vibra¬ 
tions. 

3.  A  pendulum  to  vibrate  seconds,  must  be  shorter  at 
the  equator  than  at  the  poles. 

4.  Heat  lengthens  and  cold  shortens  pendulums. 

5.  The  quicksilver  pendulum,  the  gridiron  pendulum, 
and  many  others,  have  been  contrived  to  obviate  these 
effects  of  the  change  of  temperature. 

6.  The  vibrations  of  pendulums  are  affected  by  differ¬ 
ences  in  the  density  of  the  medium  in  which  they  are 
performed. 

7.  *1  he  merit  of  the  only  contrivance  to  remedy  this 
defect  is  due  to  liittenhouse.  It  consists  in  the  use  of 
two  pendulums,  one  of  which  is  very  light,  and  placed 
in  an  inverted  position,  extending  above  the  point  of  sus¬ 
pension  of  the  other. 

8.  This  compound  pendulum  may  be  made  to  vibrate 
quicker  in  so  dense  a  medium  as  water  than  in  the  open 

air 


V 


, 

' 


■ 

•  • 

■  •  ■  ■■■■ 


I 

• 


* 

. 


'  \ 

'  ■ 

* 

. 


. 


A 


GENERAL  AND  MOST  USEFUL  SELECTION 

OF 

RECEIPTS: 

WHTCH  WILL  PROVE  OP  THE  GREATEST  UTILITY 

TO 

THE  ARTIST,  THE  MECHANIC, 

THE  FARMER,  AND  THE  LABOURING  MAN. 

EMBRACING 

THE  WHOLE  COURSE  OF  THE  ARTS, 

Selecting  and  reducing  such  parts  as  are  often  wanted,  when  the  employment 
of  the  professors  of  such  business  would  be  too  expensive  and  embar¬ 
rassing.  The  aid  of  which  will  enable  also  the  experimenter 
impelled  by  genius  to  perform  and  invent  with  greater 
ease  and  success,  in  some  cases;  while  in  others 
obstacles  will  be  removed  that  otherwise 
would  be  insurmountable. 

(323) 


f  ;  IJiffo 

' 

_ 


' 


' 

I 


' 


MISCELLANEOUS  RECEIPTS. 


'Method  for  making  Black  Writing-Ink. 

In  six  quarts  of  water,  boil  four  ounces  of  logwood  in 
chips,  cut  very  thin  across  the  grain.  The  boiling  may 
be  continued  for  nearly  an  hour,  adding,  from  time  to 
time,  a  little  boiling  water,  to  compensate  the  waste  by 
evaporation.  Strain  the  liquor  while  hot,  suffer  it  to 
cool,  and  make  up  the  quantity  equal  to  five  quarts,  by 
the  further  addition  of  cold  water.  To  this  decoction,  put 

1  lb.  avoirdupois  of  blue  galls,  coarsely  bruised ;  or 

20  oz.  of  the  best  galls,  in  sorts. 

4  oz.  of  sulphate  of  iron,  calcined  to  whiteness. 

^  oz.  of  acetate  of  copper,  previously  mixed  with  the 
decoction  till  it  forms  a  smooth  paste. 

3  oz.  of  coarse  sugar,  and 
6  oz.  of  gum-Senegal  or  Arabic. 

These  several  ingredients  may  be  introduced  one  after 
another,  contrary  to  the  advice  of  some,  who  recommend 
the  gum,  &c.  to  be  added  when  the  ink  is  nearly  made. 
The  composition  produces  the  ink  usually  called  Japan 
Ink,  from  the  high  gloss  which  it  exhibits  when  written 
with ;  and  a  small  phial  of  it  has  been  sold  for  12  cents. 

The  above  ink,  though  possessing  the  full  proportion 
of  every  ingredient  known  to  contribute  to  the  perfection 
of  ink,  will  not  cost  more,  to  those  who  prepare  it  for 
themselves,  than  the  commonest  ink  which  can  be  bought 
by  retail.  The  receipt  was  given  to  the  public  by  De- 
sormeaux.  It  answers  for  copying  letters,  by  transferring 
from  them  an  impression  to  a  damp  sheet  of  thin,  unsized 
paper,  passing  through  a  small  rolling-press. 

When  gum  is  very  dear,  or  when  no  very  high  gloss 
28 


326 


MISCELLANEOUS  RECEIPTS. 


is  required,  four  ounces  will  be  sufficient,  with  one  ounce 
and  a-half  of  sugar. 

By  using  only  12  oz.  of  galls  to  4  oz.  of  sulphate  of  iron, 
uncalcined,  omitting  the  logwood,  and  acetate  of  copper 
and  the  sugar,  and  using  only  3  oz.  of  gum,  a  good  and 
cheap  common  ink  will  be  obtained, 

Lamp-black  has  been  added  to  ink,  to  prevent  its  col¬ 
our  from  being  destroyed  by  the  action  of  the  oxy-mu- 
iatic  acid.  It  should  be  burnt  in  a  closed  crucible,  to 
ender  it  less  oily.  It  causes  the  ink  to  write  much 
less  freely,  although  it  may  be  useful  for  particular  oc 
casions. 

Red-Ink  for  Writing. 

Boil  over  a  slow  fire,  4  oz.  of  Brazil-wood,  in  small 
raspings  or  chips,  in  a  quart  of  water,  till  a  third  part  of 
the  water  is  evaporated.  Add  during  the  boiling,  two 
drams  of  alum  in  powder.  When  the  ink  is  cold,  steam 
it  through  a  fine  cloth.  Vinegar  or  stale  urine  is  often 
used  instead  of  water.  In  case  of  using  water,  I  pre¬ 
sume  a  very  small  quantity  of  sal-ammoniac  would  im¬ 
prove  this  ink. 

Blue- Ink. 

Take  Sulphate  of  Indigo,  dilute  it  with  water  till  It 
produces  the  colour  required.  It  is  with  sulphate  very 
largely  diluted,  that  the  faint  blue  lines  of  ledgers  and 
other  account  books  are  ruled.  If  the  ink  were  used 
strong,  it  would  be  necessary  to  add  chalk  to  it,  to  neu¬ 
tralize  the  acid.  The  sulphate  of  indigo  may  be  had  of 
the  woollen  dyers. 

Fire  and  Water-proof  Cement. 

To  half  a  pint  of  milk,  put  an  equal  quantity  of  vine¬ 
gar,  in  order  to  curdle  it ;  then  separate  the  curd  from 
the  whey,  and  mix  the  whey  with  four  or  five  eggs, 
beating  the  whole  well  together.  When  it  is  well  mixed, 
add  a  little  quicklime  through  a  sieve,  until  it  has  ac¬ 
quired  the  consistence  of  a  thick  paste.  With  this 


MISCELLANEOUS  RECEIPTS. 


327 


cement,  broken  vessels  and  cracks  of  all  kinds  may  be 
mended.  It  dries  quickly,  and  resists  the  action  of  water 
as  well  as  of  a  considerable  degree  of  tire. 

A  Cement  for  stopping  the  Fissures  of  Iron  Vessels. 

Take  two  ounces  of  muriate  of  ammonia,  one  ounce 
of  flowers  of  sulphur,  and  sixteen  ounces  of  cast-iron 
tilings  or  turnings;  mix  them  well  in  a  mortar,  and  keep 
the  powder  dry.  When  the  cement  is  wanted,  take  one 
part  of  this  and  twenty  parts  of  clean  iron  filings  or 
borings,  grind  them  together  in  a  mortar,  mix  them  with 
water  ta  a  proper  consistence,  and  apply  them  between 
the  joints. 

This  answers  for  flanges  of  pipes,  &c.  about  steam 
engines. 

Lutes. 

Lutes  are  compositions  which  are  employed  to  defend 
glass  and  other  vessels  from  the  action  of  tire,  or  to  till 
up  the  vacancies  which  occur,  when  separate  tubes,  foi 
the  necks  of  different  vessels,  are  inserted  into  each  other 
during  the  process  of  distillation.  Those  lutes  which 
are  exposed  to  the  action  of  fire,  are  usually  called  fire 
lutes. 

For  a  very  excellent  fire-lute,  which  will  enable  glass 
vessels  to  sustain  an  incredible  degree  of  heat,  take  frag¬ 
ments  of  porcelain,  pulverize  and  sift  them  well,  and  add 
an  equal  quantity  of  fine  clay,  previously  softened  with 
as  much  of  a  saturated  solution  of  muriate  of  soda, 
as  is  requisite  to  give  the  whole  a  proper  consistence. 
Apply  a  thin  and  uniform  coat  of  this  composition  to  the 
glass  vessels,  and  allow  it  to  dry  slowly  before  they  are 
put  into  the  fire. 

Equal  parts  of  coarse  and  refractory  clay  mixed  with 
a  little  hair,  form  a  good  lute. 

Fat  earth,  beaten  up  with  fresh  horse-dung,  Chaptal 
recommends  as  an  excellent  fire-lute,  which  he  generally 
used,  and  the  adhesion  of  which  was  such,  that  after  the 
retort  had  cracked,  the  distillation  could  be  carried  on 
and  regularly  finished. 


328  MISCELLANEOUS  RECEIPTS. 

Lutes  for  the  joining  of  such  vessels  as  retorts  and  re¬ 
ceivers,  are  varied  according  to  the  nature  of  the  vapours 
which  will  act  against  them,  in  order  not  to  employ  a 
more  expensive  and  troublesome  composition  than  the 
case  requires.  For  resisting  watery  vapours,  slips  of  wet 
bladder,  or  slips  of  wet  paper  or  linen,  covered  with  stiff 
Hour  paste,  may  be  bound  over  the  juncture. 

A  closer  and  neater  lute  for  more  penetrating  vapours 
is  composed  of  whites  of  eggs  made  into  a  smooth  paste 
with  quick-lime,  and  applied  upon  strips  of  linen.  The 
quick-lime  should  be  previously  slacked  in  the  air,  and 
reduced  to  a  fine  powder.  The  cement  should  be  ap¬ 
plied  the  moment  it  is  made ;  it  soon  dries,  becomes  very 
firm;  and  is  in  chemical  experiments  one  of  the  most 
useful  cements  known. 

Where  saline,  acrid  vapours  are  to  be  resisted,  a 
lute  should  be  composed  of  boiled  linseed  oil  intimatelv 
mixed  with  clay,  which  has  been  previously  dried,  finely 
powdered,  and  sifted.  This  is  called  fat  lute.  It  is  ap¬ 
plied  to  the  junctures,  as  the  undermost  layers,  and  is 
secured  in  its  place  by  the  white  of  egg-lute  last  mention¬ 
ed,  which  is  tied  on  with  pack-thread. 


Blacking,  to  make. 

Put  1  gallon  of  vinegar  into  a  stone  jug,  add  1  lb.  of 
ivory-black,  well  pulverized,  1  a  lb.  of  loaf  sugar,  £  an 
oz.  of  oil  of  vitriol,  and  1  oz.  ot  sweet  oil ;  incorporate  the 
whole  by  stirring. 

This  is  a  blacking  of  very  great  repute  in  different 
countries,  and  on  which  great  praise  has  been  verv  de¬ 
servedly  bestowed.  It  has  decidedly  been  ascertained, 
from  experience,  to  be  less  injurious  to  the  leather,  than 
most  public  blackings ;  and  it  certainly  produces  a  fine 
jet  polish,  which  is  rarely  equalled,  and  never  yet  sur* 


MISCELLANEOUS  RECEIPTS. 


329 


VARNISHES. 

To  dissolve  Copal  in  Alcohol. 

Copal,  which  is  called  gum  copal,  but  which  is  not, 
strictly,  either  a  gum  or  a  resin,  is  the  hardest  and  least 
changeable  of  all  substances  adapted  to  form  varnishes, 
by  their  dissolution  in  spirit,  or  essential,  or  fat  oils.  It, 
therefore,  forms  the  most  valuable  varnishes  ;  though  we 
shall  give  several  receipts  where  it  is  not  employed, 
which  form  cheaper  varnishes,  sufficiently  good  for  many 
purposes,  adding  only  the  general  rule,  that  no  varnish 
must  be  expected  to  be  harder  than  the  substance  from 
which  it  is  made. 

To  dissolve  copal  in  alcohol,  dissolve  half  an  ounce  of 
camphor  in  a  pint  of  alcohol ;  put  it  into  a  circulating 
glass,  and  add  4  oz.  of  copal  in  small  pieces ;  set  it  in  a 
sand-heat,  so  regulated  that  the  bubbles  may  be  counted 
as  they  rise  from  the  bottom,  and  continue  the  same  heat 
till  the  solution  is  completed. 

The  process  above-mentioned  will  dissolve  more  copal 
than  the  menstruum  will  retain  when  cold.  The  most 
economical  method  Will  therefore  be,  to  set  the  vessel 
which  contains  the  solution  by  for  a  few  days,  and,  when 
it  is  perfectly  settled,  pour  off  tfye  clear  varnish,  and  leave 
the  residue  for  future  operation. 

The  solution  of  copal  thus  obtained  is  very  bright.  It 
is  an  excellent  varnish  for  pictures,  and  would,  doubtless, 
be  an  improvement  in  japanning,  v'here  the  stoves  used 
for  drying  the  varnished  articles  would  drive  off  the 
camphor,  and  leave  the  copal  clear  and  colourless  in  the 
work. 

To  dissolve  Copal  in  Spirits  of  Turpentine. 

Reduce  2  oz.  of  copal  to  small  pieces,  and  put  them 
into  a  proper  vessel.  Mix  a  pint  of  the  best  spirits  ot 
turpentine  with  one  eighth  of  spirits  of  sal  ammoniac; 
shake  them  well  together,  put  them  to  the  copal,  cork 
28* 


330 


MISCELLANEOUS  RECEIPTS. 


the  glass,  and  tie  it  over  with  a  string  or  wire,  making  a 
small  hole  through  the  cork.  Set  the  glass  in  a  sand- 
heat  so  regulated  as  to  make  the  contents  boil  as  quickly 
as  possible,  but  so  gently  that  the  bubbles  may.  be  counted 
as  they  rise  from  the  bottom.  The  same  heat  must  be 
kept  up  exactly  till  the  solution  is  complete. 

It  requires  the  most  accurate  attention  to  succeed  in 
this  operation.  After  the  spirits  are  mixed,  they  should 
be  put  to  the  copal,  and  the  necessary  degree  of  heat  b 
given  as  soon  as  possible,  and  maintained  with  the  utmos 
regularity.  If  the  heat  abates,  or  the  spirits  boil  quicker 
than  is  directed,  the  solution  will  immediately  stop,  and 
ft  will  afterwards  be  in  vain  to  proceed  with  the  same 
materials ;  but  if  properly  managed  the  spirit  of  sal 
ammoniac  will  be  seen  gradually  to  descend  from  the 
mixture,  and  attack  the  copal,  which  swells  and  dissolves, 
excepting  a  very  small  quantity  which  remains  undis¬ 
solved. 

It  is  of  much  consequence  that  the  vessel  should  not 
be  opened  till  some  time  after  it  has  been  perfectly  cold ; 
for  if  it  contain  the  least  warmth  when  opened,  the  whole 
contents  will  be  blown  out  of  the  vessel. 

Whatever  quantity  is  to  be  dissolved,  should  be  put 
into  a  glass  vessel  capable  at  least  of  containing  four 
times  as  much,  and  it  should  be  high  in  proportion  to  the 
width. 

This  varnish  is  of  a  deep  rich  colour,  when  viewed  in 
the  bottle,  but  seems  to  give  no  colour  to  the  pictures 
upon  which  it  is  laid.  If  it  be  left  in  the  damp,  it  re¬ 
mains  racky,  as  it  is  called,  a  long  time;  but  if  kept  in 
a  warm  room,  or  placed  in  the  sun,  it  dries  as  well  as 
any  other  turpentine  varnish,  and  when  dry  it  appears 
to  be  as  durable  as  any  other  solution  of  copal.  ' 

Copal  may  also  be  dissolved  in  spirits  of  turpentine  by 
the  assistance  of  camphor. 

Turpentine  varnishes  dry  more  slowly  than  those  made 
with  alcohol,  and  are  less  hard  ;  but  they  are  not  so  lia* 
ble  to  crack. 


MISCELLANEOUS  RECEIPTS. 


333 


To  dissolve  Copal  in  fixed -Oil. 

Melt,  in  a  perfectly  clean  vessel,  by  a  very  slow  heat, 
one  pound  of  clear  copal ;  to  this,  add  from  one  to  two 
quarts  of  drying  linseed  oil.  When  these  ingredients  are 
thoroughly  mixed,  remove  the  vessel  from  the  fire,  and 
keep  constantly  stirring  it,  till  nearly  cold ;  then  add  a 
pound  of  spirits  of  turpentine.  Strain  the  varnish  through 
a  piece  of  cloth,  and  keep  it  for  use.  The  older  it  is,  the 
more  drying  it  becomes. 

This  varnish  is  very  proper  for  wood-work,  house  and 
carriage  painting. 

Seed-lac  Varnish. 

Take  three  ounces  of  seed-lac,  and  put  it,  with  a  pint 
of  spirits  of  wine,  into  a  bottle,  of  which  it  will  not  fill 
more  than  two-thirds.  Shake  the  mixture  well  together, 
and  place  it  in  a  gentle  heat,  till  the  seed-lac  appears 
to  be  dissolved:  the  solution  will  be  hastened  by  shaking 
the  bottle  occasionally.  After  it  has  stood  some  time,  pour 
off  the  clear  part,  and  keep  it  for  use  in  a  well-stopped 
bottle.  The  seed-lac  should  be  purified  before  it  is  used, 
by  washing  it  in  cold  water,  and  it  should  be  in  coarse 
powder,  when  added  to  the  spirit. 

This  varnish  is  next  to  that  of  copal  in  hardness,  and 
has  a  reddish-yellow  colour :  it  is,  therefore,  only  to  be 
used  where  a  tinge  of  that  kind  is  not  injurious. 

Shell-lac  Varnish. 

Take  five  oz.  of  the  best  shell-lac,  reduce  it  to  a  gross 
powder,  and  put  it  into  a  bottle  in  a  gentle  heat,  or  a 
warm,  close  apartment,  where  it  must  continue  two  or 
three  days,  but  should  be  frequently  well  shaken.  The 
lac  will  then  be  dissolved,  and  the  solution  should  then 
be  filtered  through  a  flannel  bag ;  and,  when  the  portion 
that  will  pass  through  freely  is  come  off  it  should  be  kept 
for  use  in  well-stopped  bottles. 

The  portion  which  can  only  be  made  to  pass  through 
the  bag  by  pressure,  may  be  reserved  for  coarse  purposes. 


332 


MISCELLANEOUS  RECEIPTS. 


Shell-lac  varnish  is  rather  softer  than  seed-lac  varnish, 
but  it  is  the  best  of  varnishes  for  mixing  with  colours  to 
paint  with,  instead  of  oil,  from  its  working  and  spreading 
better  in  the  pencil. 

Varnish  for  Toys,  Silvered  Clock-faces,  and  Furniture , 
not  exposed  to  hardship. 

Dissolve  two  ounces  of  gum-mastic,  and  eight  ounces 
of  gum-sandrach,  in  a  quart  of  alcohol ;  then  add  four 
ounces  of  Venice  turpentine.  The  addition  of  a  little  of 
the  whitest  part  of  gum-benjamin  will  render  the  varnish 
less  liable  to  crack. 


Atnher  Varnish. 

Amber  forms  a  very  excellent  varnish :  its  solution 
may  be  effected  by  boiling  it  in  drying  linseed  oil. 

Oil-varnishes,  which  have  become  thick  by  keeping, 
are  made  thinner  with  spirits  of  turpentine. 

A  Varnish  for  Copper-plate  Prints. 

Prepare  water  by  dissolving  in  it  some  isinglass ;  lay 
on,  with  a  soft  brush,  a  coat  of  this.  Let  dry.  Put  on 
another,  if  necessary.  Let  dry.  Then  lay  on  another, 
of  the  following  varnish. — True  French  spirit  of  wine, 
half  a  pound;  gum-elemi,  two  drachms,  and  sandarach, 
three. 

A  curious  and  easy  Varnish  to  engrave  wrth  aquafortis. 

Lay  on  a  copper-plate  as  smooth  and  equal  a  coat  as 
possible,  of  linseed  oil.  Set  the  plate  on  a  gentle  heat, 
that  the  oil  may'congeal,  and  dry  itself  in.  When  you 
find  it  has  acquired  the  consistence  of  a  varnish,  then 
you  may  draw  with  a  steel  point,  in  order  to  etch  your 
copper,  and  put  on  the  aquafortis  afterwards. 

A  Varnish  to  gild  with,  without  Gold. 

Take  half  a  pint  of  spirits  of  wine,  in  which  you  dis¬ 
solve  one  drachm  of  sallion,  and  half  a  drachm  of  dra 


MISCELLANEOUS  RECEIPTS. 


333 

gon’s  blood,  both  previously  well  pulverized  together. 
Add  this  to  a  certain  quantity  of  shell-lac  varnish,  and  set 
it  on  the  fire  with  two  drachms  of  soccotrine  aloes. 

Japanning. 

Japanning  is  the  art  of  varnishing  in  colours,  and  is 
frequently  combined  with  painting. 

The  substances  proper  for  japanning,  are  wood,  metal, 
with  all  others  which  retain  a  determinate  form,  and  are 
capable  of  sustaining  the  operation  of  drying  the  var¬ 
nish.  Paper  and  leather,  therefore,  when  wrought  into 
forms  in  which  they  remain  stretched,  stiff,  and  inflexible 
are  very  common  subjects  for  japanning. 

The  article  to  be  japanned  is  first  rendered  smooth 
and  perfectly  clean,  it  is  then  brushed  over  with  two  or 
three  coats  of  seed-lac  varnish,  (see  under  the  head  of 
varnishes)  except  that  the  coarsest  varnish  will  answer 
the  purpose.  The  varnish  thus  laid  on  is  called  the 
priming.  The  next  operation  is  to  varnish  the  article 
again  with  the  best  varnish  previously  mixed  with  a  pig¬ 
ment  of  the  tint  desired.  This  is  called  the  grounding ; 
if  the  subject  is  to  exhibit  any  painting,  the  objects  are 
painted  upon  it,  in  colours  mixed  up  with  varnish,  and 
used  in  the  same  manner  as  for  oil-painting.  The  whole 
is  then  covered  with  additional  coats  of  transparent 
varnish,  and  all  that  remains  to  be  done,  is  to  dry  and  v 
polish  it. 

Japanning  should  always  be  executed  in  warm  apart¬ 
ments,  as  cold  and  moisture  are  alike  injurious;  and  all 
the  articles  should  be  warmed  before  any  varnish  is  ap¬ 
plied  to  them.  One  coat  of  varnish,  also,  must  be  dry 
before  another  is  laid  on.  Ovens  are  employed  to  hasten 
the  perfect  drying  of  the  w7ork. 

All  the  coloured  pigments  employed  in  oil  or  water, 
answer  perfectly  well  in  varnish,  combined  with  which 
vehicle,  many  of  those  which  fly  in  oil  are  perfectly 
unchangeable.  The  manner  in  which  the  colours  are 
mixed  with  the  varnish  is  extremely  simple  and  easy ; 
they  are  first  reduced,  by  the  usual  means  of  washing 


334 


MISCELLANEOUS  RECEIPTS. 


nnd  levigation,  to  the  finest  state  possible ;  and  the  var¬ 
nish  being  contained  in  a  bottle,  they  are  added  to  it,  til! 
the  requisite  body  of  colour  is  obtained,  the  mixture 
being  rendered  complete  by  stirring  or  shaking  the  bottle. 
When  a  single  colour  is  intended,  the  varnish  employed 
is  of  no  consequence,  if  it  be  hard  enough  for  the  work, 
and  not  possessed  of  any  colour  inconsistent  with  the  tint 
required ;  but  for  painting  with,  shell-lac  varnish  is  the 
best,  and  easiest  to  work :  it  is,  therefore,  employed  in 
all  cases  where  its  colour  permits,  and  for  the  lightest 
colours,  mastic  varnish  is  employed,  unless  the  fineness 
of  the  work  admits  the  use  of  copal  dissolved  in  spirits 
of  wane. 

To  spare  varnish,  the  priming  may  be  composed  of 
size  mixed  with  whiting,  to  give  it  a  body,  as  some  sub¬ 
stances  require  much  varnish  to  saturate  them ;  but 
w7ork  primed  with  size  is  never  durable ;  it  is  liable  to 
crack  and  fly  off-  with  the  least  violence,  which  never 
happens  to  work  into  which  the  varnish  can  sink.  Var¬ 
nish  cannot  sink  into  metals,  and  this  is  the  reason  that 
japanned  metal,  for  example  a  japanned  tin-plate  tray,  is 
of  less  value  than  a  paper  one.  The  battering  which 
this  piece  of  furniture  sustains  in  its  use,  soon  separates 
the  japan  from  it  in  flakes,  or  scales;  which  never  hap¬ 
pens  to  the  paper,  because  the  japan  forms  a  part  of  its 
substance. 

It  may  be  observed,  that  only  wood,  paper,  leather, 
and  similar  substances,  require  priming ;  metals  require 
none,  because  they  admit  no  varnish  into  them,  and 
therefore  the  ground  is  applied  to  them  immediately. 

The  priming  and  grounds  are  all  laid  on  with  brushes 
made  of  bristles:  the  painting  will  of  course  often  re¬ 
quire  a  camels’-hair  pencil. 

Of  Japan  Grounds. 

Red. — Vermilion  makes  a  fine  scarlet,  but  its  appear¬ 
ance  in  japanned  work  is  much  improved  by  glazing  it 
with  a  thin  coat  of  lake,  or  even  rose  pink. 

Indian  lake,  when  good,  is  perfectly  soluble  in  spirits 


MISCELLANEOUS  RECEIPTS.  335 

of  wine,  and  produces  a  fine  crimson,  but  is  not  often  to 
be  obtained. 

Yellow . — King’s  yellow,  turbith  mineral,  and  Dutch 
pink,  all  form  very  bright  yellows,  and  the  latter  is  very 
cheap.  Seed-lac  varnish  assimilates  with"  yellow  very 
well ;  and  when  they  are  required  very  bright,  an  im¬ 
provement  may  be  effected  by  infusing  turmeric  in  the 
varnish  which  covers  the  ground. 

Green. — Distilled  verdigris  laid  on  a  ground  of  leaf 
gold,  produces  the  brightest  of  all  greens;  other  greens 
may  be  formed  by  mixing  king’s  yellow  and  bright  prus- 
sian  blue,  or  turbith  mineral  and  prusslan  blue,  or  Dutch 
pink  and  verdigris. 

Blue. — Prussian  blue,  orverditer  glazed  with  Prussian 
blue  or  smalt. 

White. — White  grounds  are  obtained  with  greater  dif¬ 
ficulty  than  any  other.  One  of  the  best  is  prepared  by 
grinding  up  flock-white,  or  zinc-white,  with  one  sixth  of 
its  weight  of  starch,  and  drying  it ;  it  is  then  tempered, 
like  the  other  colours,  using  the  mastic  varnish  for  com¬ 
mon  uses;  and  that  of  the  best  copal  for  the  finest.  Par¬ 
ticular  care  should  be  taken,  that  the  copal  for  this  use 
be  made  of  the  clearest  and  whitest  pieces.  Seed-lac 
may  be  used  as  the  uppermost  coat,  where  a  very  deli¬ 
cate  white  is  not  required,  taking  care  to  use  such  as  is 
least  coloured. 

Black. — Ivory-black  or  lamp-black ;  but  if  the  lamp¬ 
black  be  used,  it  should  be  previously  calcined  in  a  closed 
crucible. 

Black  grounds  may  be  formed  on  metal,  by  drying 
linseed  oil  only,  when  mixed  with  a  little  lamp-black. 

The  work  is  then  exposed  in  a  stove  to  a  heat  which 
will  render  the  oil  black.  The  heat  should  be  low  at 
first,  and  increased  very  gradually,  or  it  will  blister.  This 
kind  of  japan  requires  no  polishing.  It  is  extensively 
used  for  defending  articles  of  iron-mongery  from  rust. 

Tortoise-shell  ground  for  metal. — Cover  the  plates 
intended  to  represent  the  transparent  parts  of  the  tor- 
i  toise-shell,  with  a  thin  coat  of  vermilion  in  seed-lac 


336  MISCELLANEOUS  RECEIPTS. 

varnish.  Then  brush  over  the  whole  with  a  varnish 
composed  of  linseed  oil  boiled  with  umber  until  it  is 
almost  a  black.  The  varnish  may  be  thinned  with  oil 
of  turpentine  before  it  is  used.  When  the  work  is  done, 
it  may  be  set  in  an  oven,  with  the  same  precautions  as 
the  black  varnish  last  named. 

Polishing  of  varnished  and  japanned  work. 

Pictures  and  other  subjects,  to  which  only  a  single 
coat  or  two  of  thin  varnish  is  given,  are  generally  left  to 
the  polish  which  the  varnish  naturally  possesses,  or 
brightened  only  by  rubbing  it  with  a  woollen  cloth,  after 
it  is  dry;  but  wherever  several  coats  of  varnish  or 
japan  are  laid  on,  a  glossy  surface  is  produced  by  the 
means  used  to  polish  metals;  the  surface  having  been 
suffered  to  become  completely  dry  and  hard. 

When  the  coat  of  varnish  is  very  thick,  the  surface 
may  be  rubbed  with  pumice-stone  and  oil,  until  it  be¬ 
comes  uniformly  smooth;  the  pumice  should  first  be 
reduced  to  a  smooth  fiat  face  by  rubbing  it  on  a  piece  of 
freestone,  or  something  to  answer  the  same  purpose.. 
The  japanned  or  varnished  surface  may  afterwards  be 
rubbed  with  pumice  reduced  to  an  impalpable  powder. 
The  finishing  may  be  given  by  oil  and  woollen  rag  only. 

When  the  varnish  is  thinner,  and  of  a  more  delicate 
nature,  it  may  be  rubbed  with  tripoli  or  rotten-stone,  in 
fine  powder,  finishing  with  oil  as  before.  W  hen  the 
ground  is  white,  putty  or  Spanish  white,  finely  washed, 
may  be  used  instead  of  rotten-stone,  of  which  the  colour 
might  have  some  tendency  to  injure  the  ground. 

Preparation  of  Drying  Linseed  Oil. 

Frequent  reference  has  been  made  to  the  use  of  drying 
linseed  oil :  it  may  be  necessary  to  observe,  that  to  render 
linseed  oil  drying  consists  simply  in  mixing  it  with  litharge, 
or  any  oxide  of  lead,  boiling  it  slowly  for  some  time,  and 
straining  it  from  the  sediments  after  it  has  stood  to  clarify. 
The  oil  thus  treated,  beomes  thicker  as  it  imbibes  oxygen 
from  the  oxide,  and  acquires  the  property  of  drying  much 


MISCELLANEOUS  RECEIPTS.  33? 

sooner  than  before.  An  ounce  of  litharge  may  be  used 
m  every  pound  of  oil. 

To  render  Boots  and  Shoes  water-proof. 

Takc  one  pint  of  drying  oil,  two  ounces  of  yellow  wax, 
two  ounces  spirits  of  turpentine,  and  half  an  ounce  of 
Burgundy  pitch,  melt  them  over  a  slow  fire,  and  thorough¬ 
ly  incorporate  them  by  stirring.  Lay  this  mixture  on 
new  shoes  and  boots,  either  in  the  sun  or  at  some  dis 
lance  from  the  fire,  with  a  sponge  or  brush,  and  repeat 
ihe  operation  as  often  as  they  become  dry,  until  they  are 
fully  saturated.  The  shoes  and  boots  thus  prepared, 
ought  not  to  be  worn  until  the  leather  has  become  per¬ 
fectly  dry  and  elastic.  They  will  then  be  found  imper 
vious  to  moisture,  and  tbeir  durability  will  be  increased. 

Method  of  preparing  a  cheap  Substitute  for  Oil  Paint. 

It  often  happens  that  people  do  not  choose,  or  cannot 
employ  oil-painting  in  the  country,  either  because  it  does 
not  dry  soon  enough,  ana  has  a  disagreeable  smell,  or 
because  it  is  too  costly.  Ludicke  employed  with  the 
greatest  success  the  following  composition  for  painting 
ceilings,  gates,  doors,  and  even  furniture. 

Take  fresh  curds,  and  bruise  the  lumps  on  a  grinding- 
stone,  or  in  an  earthen  pan  or  mortar,  with  a  spatula. 
After  this  operation,  put  them  in  a  pot  with  an  equal 
quantity  of  lime,  well  quenched,  and  become  thick 
enough  to  be  kneaded:  stir  the  mixture  well,  without 
adding  water,  and  a  whitish  semi-fluid  mass  will  be  ob¬ 
tained,  which  may  be  applied  with  great  facility  like 
paint,  and  which  dries  very  rapidly.  It  must  be  employed 
the  day  it  is  prepared,  as  it  will  become  too  thick  the 
following  day.  Ochre,  armenian  bole,  and  all  colours 
which  hold  with  lime,  may  be  mixed  with  it,  according 
to  the  colour  desired  ;  but  care  must  be  taken,  that  the 
addition  of  colour  made  to  the  first  mixture  of  curds  and 
lime,  contain  very  little  water,  or  it  will  diminish  the 
durability  of  the  painting. 

When  two  coats  ot  this  painting  have  been  laid  on  it 
29  '  W 


MISCELLANEOUS  RECEIPTS. 


338 

may  be  polished  with  a  piece  of  woollen  cloth,  or  other 
proper  substance,  and  it  will  become  as  bright  as  varnish. 
This  kind  of  painting,  besides  its  cheapness,  possesses  the 
advantage  of  admitting  the  coats  to  be  laid  on  and  pol 
khed  in  one  Jay  ;  as  it  dries  speedily,  and  has  no  smell. 

A  Cement  which  answers  for  cast  iron  Pipes ,  or 
wooden  Logs. 

Take  12  or  14  lbs.  of  fine  cast  iron  borings,  put  them 
in  a  vessel  with  as  much  water  as  will  just  wet  them 
through ;  mix  with  them  A  lb.  of  pounded  sal  ammo¬ 
niac,  and  2  oz.  of  flour  of  sulphur ;  mix  all  well  together, 
and  let  stand  three  or  four  hours  :  they  are  then  ready 
for  use.  If  not  used  immediately,  cover  them  with  water 
till  used. 

Bronzing. 

Bronze  of  a  good  quality  acquires,  by  oxidation,  a  fine 
green  tint,  called  patina  antiaua.  Corinthian  brass  re¬ 
ceives,  in  this  way,  a  beautiful  clear  green  colour.  This 
appearance  is  imitated  by  an  artificial  process,  called 
bi'onzing.  A  solution  of  sal  ammoniac  and  salt  of  sorel 
in  vinegar  is  used  for  bronzing  metals.  Any  number  of 
layers  may  be  applied,  and  the  shade  becomes  deeper  in 
proportion  to  the  number  applied.  For  bronzing  sculp¬ 
tures  of  wood,  plaster-figures,  &c.,  a  composition  of  yel¬ 
low  ochre,  Prussian  blue,  and  lamp-black,  dissolved  in 
glue- water,  is  employed. 

Caoutchouc,  or  India  Rubber,  how  dissolved,  uses,  6fC. 

Caoutchouc  is  brought  principally  from  South  Ameri¬ 
ca:  the  juice,  obtained  from  incisions,  is  applied  in  suc¬ 
cessive  layers,  over  a  mould  of  clay,  and  dried  by  exposure 
to  the  sun,  and  to  the  smoke  from  burning  fuel.  When 
perfectly  dry,  the  mould  is  broken,  leaving  the  caout 
chouc  in  the  form  of  a  hollow  ball.  It  is  insoluble  in 
alcohol  and  in  water.  Sulphuric  ether,  when  purified  by 
washing  in  water,  dissolves  it ;  and,  by  evaporation,  the 
iaoutchouc  may  be  discovered  unchanged. 


MISCELLANEOUS  RECEIPTS.,  339 

Oil  of  turpentine  softens  it,  and  forms  with  it  a  sort  of 
paste  that  may  be  spread  as  a  varnish ;  but  it  is  very 
long  in  drying.  The  fluid  now  commonly  used  to  dissolve 
it  is  the  purified  naphtha  from  coal  tar,  which  is,  at  the 
same  time,  a  cheap  and  effectual  solvent,  and  which 
does  not  change  its  properties.  This  solution  is  employed 
to  give  a  thin  covering  of  caoutchouc  to  cloth,  which  is 
thus  rendered  impervious  to  moisture.  Caoutchouc  is 
also  readily  soluble  in  cajeput  oil. 

Caoutchouc,  from  its  softness,  elasticity,  and  impene¬ 
trability  to  water,  is  applied  to  the  formation  of  cathe¬ 
ters,  bougies,  and  tubes  for  conveying  gases.  These 
are  formed  by  twisting  a  slip  of  it  round  a  rod,  and 
causing  the  edges  to  adhere  by  pressure,  when  softened 
by  maceration  in  warm  water.  It  is  also  used  very  ex¬ 
tensively  in  this  country  for  over-shoes;  and  its  solution 
in  oils  forms  a  flexible  varnish. 

The  following  Composition  will  render  Boots  or  Shoes 
impervious  to  Water. 

Take  neat’s-foot  oil,  and  dissolve  in  it  caoutchouc,  a 
sufficient  quantity  to  form  a  kind  of  varnish ;  rub  this  on 
the  boots.  This  is  sufficient. 

N.  B.  The  oil  must  be  placed  where  it  is  warm,  the 
caoutchouc  put  into  it  in  parings.  It  will  take  several 
days  to  dissolve  it. 

An  excellent  Salve  for  Cuts,  Bruises,  Sores,  fyc. 

Take  1^  oz.  of  olive  oil,  2  oz.  of  white  diacula,  and  2 
oz.  of  bees’-wax ;  let  these  ingredients  be  dissolved  toge¬ 
ther,  and  the  salve  is  formed.  This  salve  I  have  tried 
to  my  satisfaction,  and  found  it  answer  exceedingly  well. 

Various  Cements. 

The  joints  of  iron  pipes,  and  the  flanges  of  steam  en¬ 
gines,  are  cemented  with  a  mixture  composed  of  sulphur, 
and  muriate  of  ammonia,  together  with  a  large  quantity 
of  iron  chippings. 

The  putty  of  glaziers  is  a  mixture  of  linseed  oil  and 


340 


MISCELLANEOUS  RECEIPTS. 


powdered  chalk.  Plaster  of  Paris,  dried  by  heal,  and 
mixed  with  water,  or  with  rosin  and  wax,  is  used  for 
uniting  pieces  of  marble.  A  cement  composed  of  brick- 
dust  and  rosin,  or  pitch,  is  employed  by  turners,  and 
some  other  mechanics,  to  confine  the  material  on  which 
they  are  working.  Common  paint,  made  of  white  lead 
and  oil,  is  used  to  cement  china-ware.  So  also  are  resi¬ 
nous  substances,  such  as  mastic  and  shell-lac,  or  isinglass 
dissolved  in  proof-spirit  or  water.  The  paste  of  book 
binders,  and  paper-hangers,  is  made  by  boiling  flour 
Rice-glue  is  made  by  boiling  ground  rice  to  the  consist¬ 
ence  of  a  thin  jelly.  Wafers  are  made  of  flour,  isinglass, 
yeast,  and  white  of  eggs,  dried  in  thin  layers  upon  tin 
plates,  and  cut  by  a  circular  instrument.  They  are 
coloured  by  red  lead  &c.  Sealing-wax  is  composed  of 
shell-lac  and  rosin,  and  is  commonly  coloured  with  ver¬ 
milion.  Common  glue  is  most  usually  employed  for  uniting 
wood  and  similar  porous  substances.  It  does  not  answer 
for  surfaces  impervious  to  water,  such  as  metals,  glass, 
&c.  The  cements  mostly  used  in  building  are  composed 
of  lime  and  sand.  The  lime  adheres  to  and  unites  the 
particles  of  sand.  Cements  thus  made  increase  in  strength 
for  an  indefinite  period.  Fresh  sand  wholly  silicious  and 
sharp,  is  the  best.  That  taken  from  the  sea  shore  is 
unfit  for  making  mortar,  as  the  salt  is  apt  to  deliquesce 
and  weaken  the  mortar.  The  amount  of  sand  is  always 
greater  than  that  of  lime.  From  two  to  four  parts  of 
sand  are  used,  according  to  the  quality  of  the  lime  and 
the  labour  bestowed  on  it. 

An  excellent  Cement  for  Paper,  Cloth,  <§-c.  or  for  the 
use  of  Block-Cutters 

Lv  fastening  the  hatting  into  the  figures,  is  made  by 
stirring  a  quantity  of  raw  flour  into  a  rather  thin  solution 
of  gum-senegal  water. 

Gilding. 

The  art  of  gilding  at  the  present  day,  is  performed 
either  upon  metals,  or  upon  wood,  leather,  parchment, 


MISCELLANEOUS  RECEIPTS. 


34 1 


or  paper ;  and  there  are  three  distinct  methods  in 
general  practice,  vsz.  wash,  or  water-gilding,  in  which 
the  gold  is  spread,  whilst  reduced  to  a  fluid  state, 
by  solution  in  mercury;  leaf-gilding,  cither  burnished 
or  in  oil,  performed  by  cementing  their  leaves  of  gold 
upon  the  work,  either  by  size  or  by  oil ;  japanner's- 
gilding,  in  which  gold  dust  or  powder  is  used  instead  of 
leaves.  Gilding  on  copper  is  performed  with  an  amalgam 
of  gold  and  mercury.  The  surface  of  the  copper,  being 
freed  from  oxide,  is  covered  with  the  amalgam,  and 
afterwards  exposed  to  heat  till  the  mercury  is  driven  off, 
leaving  a  thin  coat  of  gold.  It  is,  also,  performed  by 
dipping  a  linen  rag  in  a  saturated  solution  of  gold,  and 
burning  it  to  tinder.  The  black  powder  thus  obtained 
is  rubbed  on  the  metal  to  be  gilded,  with  a  cork  dipped 
in  salt  water,  till  the  gilding  appears.  Iron  or  steel  is 
gilded  by  applying  gold  leaf  to  the  metal  after  the  sur¬ 
face  has  been  well  cleaned,,  and  heated  until  it  has 
acquired  the  blue  colour,  which  at  a  certain  temperature 
it  assumes.  The  surface  is  previously  burnished,  and  the 
process  is  repeated  when  the  gilding  is  required  to  be 
more  durable.  It  is,  also,  performed  by  diluting  a  solu¬ 
tion  of  gold  in  nitro-muriatic  acid,  with  alcohol,  and 
applying  to  the  clean  surface.  A  saturated  solution  of 
gold  in  nitro-muriatic  acid,  and  mixed  with  three  times 
its  weight  of  sulphuric  ether,  dissolves  the  muriate  of 
gold,  and  the  solution  is  separated  from  the  acid  beneath. 
To  gild  the  steel,  it  is  merely  necessary  to  dip  it,  the  sur¬ 
face  being  previously  well  polished  and  cleaned,  in  the 
ethereal  solution,  for  an  instant,  and  on  withdrawing  it, 
to  w7ash  it  instantly  by  agitation  in  water.  By  this  method 
steel  instruments  are  very  commonly  gilt. 

Method  of  Preparing  and  Using  Glue. 

Set  a  quart  of  water  on  the  fire,  then  put  in  about 
half  a  pound  of  good  glue,  and  boil  them  gently  together 
till  the  glue  be  entirely  dissolved,  and  of  a  due  consistence 

When  glue  is  to  be  used,  it  must  be  made  thoroughly 
hot,  after  which  with  a  brush  dipped  in  it  besmear  the 
29  * 


342  MISCELLANEOUS  RECEIPTS. 

faces  of  the  joints  as  thick  as  possible ;  then,  clapping 
them  together,  glide  or  run  them  lengthwise  one  upon 
another  two  or  three  times,  to  settle  them  close,  so  let 
them  stand  till  they  are  dry  and  firm.  Parchment-glue 
is  made  by  boiling  gently  shreds  of  parchment  in  water, 
in  proportion  of  one  pound  of  the  former  to  six  of  the 
latter,  till  it  be  reduced  to  one  quart ;  the  fluid  is  then 
strained  from  the  dregs,  and  afterwards  boiled  to  the 
consistence  of  glue.  Isinglass-glue  is  made  in  the  same 
way;  but  this  is  improved  by  dissolving  the  isinglass  in 
alcohol,  by  means  of  a  gentle  heat. 

China  or  Indian  Ink. 

Dr.  Lewis,  on  examining  this  substance,  found  that  the 
ink  consisted  of  a  black  sediment,  totally  insoluble  in 
water,  which  appeared  to  be  of  the  nature  of  the  purest 
lamp-black,  and  of  another  substance  soluble  in  water, 
and  which  putrefied  by  keeping,  and  when  evaporated, 
left  a  tenacious  jelly,  exactly  like  glue,  or  isinglass.  It 
appears  probable,  therefore,  that  it  consists  of  nothing 
more  than  these  two  ingredients,  and  probably  may  be 
imitated  with  perfect  accuracy  by  using  a  very  fine  jelly, 
like  isinglass,  or  size,  and  the  finest  lamp-black,  and  in¬ 
corporating  them  thoroughly.  The  finest  lamp-black 
known  is  made  from  ivory  shavings,  and  thence  called 
ivory  black. 

Ivory  Dyeing. 

This  substance  may  be  dyed  or  stained  black,  by  a 
solution  of  brass  and  a  decoction  of  logwood  ;  a  green,  by 
a  solution  of  verdigris ;  a  red,  by  being  boiled  with  Bra¬ 
zil-wood  in  lime-water. 

To  prevent  the  smoking  of  lamp  oil. 

Steep  your  wick  in  vinegar,  and  dry  it  well  before 
you  use  it. 

Portable  balls  for  removing  spots  from  clothes  in 

general. 

Take  fuller’s  earth  perfectly  dried,  so  that  it  crumbles 
to  powder,  moisten  it  with  the  clear  juice  of  lemons, 


MISCELLANEOUS  RECEIPTS. 


343 


and  add  a  small  quantity  of  pure  pearlash ;  then  work 
and  knead  the  whole  carefully  together,  till  it  acquires 
the  consistency  of  a  thick  elastic  paste  :  form  it  into  con¬ 
venient  small  balls,  and  expose  them  to  the  heat  of  the 
sun,  in  which  they  ought  to  be  carefully  dried.  In  this 
state  they  are  fit  for  use  in  the  manner  following:  first 
moisten  the  spot  on  the  clothes  with  water,  then  rub  it 
with  the  ball  just  dissolved,  and  sutfer  it  again  to  dry  in 
the  sun :  after  having  washed  the  spot  with  pure  water 
it  will  disappear. 

Easy  and  safe  method  of  discharging  grease  spots  from 

woollen. 

Fuller’s  earth,  or  tobacco-pipe  clay,  being  first  wet  on 
an  oil  spot,  absorbs  the  oil  as  the  water  evaporates,  and 
leaves  the  vegetable  or  animal  fibres  of  cloth  clean,  on 
being  beaten  or  brushed  well.  When  the  spot  is  occa¬ 
sioned  by  tallow  or  wax,  it  is  necessary  to  treat  the  part 
cautiously  by  an  iron  on  the  fire,  while  the  cloth  is  dry¬ 
ing.  Jn  some  kind  of  goods,  bran  or  raw  starch  may  be 
used  with  advantage. 

To  take  spots  out  of  Silk. 

Rub  the  spots  with  spirits  of  turpentine:  this  spirit 
exhaling,  carries  off  with  it  the  oil  that  causes  the  spot. 

To  take  spots  out  of  Cloths,  Stuff's,  Silks,  Cotton  and 

Linen. 

Take  one  quart  of  spring-water,  put  in  it  a  little  fine 
white  powder  about  the  size  of  a  walnut,  and  a  lemon 
cut  in  slices,  mix  these  well  together,  and  let  it  stand 
twenty-four  hours  in  the  sun.  This  liquid  takes  out  all 
spots,  whether  pitch,  grease,  or  oil,  as  well  in  hats,  as 
cloths  and  stuffs,  silk  or  cotton,  and  linen.  As  soon  as 
the  spot  is  taken  out,  wash  the  place  with  clean  water , 
for  cloths  of  deep  colour,  add  to  a  spoonful  of  the  mix 
ture,  a  quantity  of  water  to  dilute  it. 

To  render  Cloth,  wind  and  rain  proof. 

Boil  together  2  lbs.  of  turpentine,  and  1  lb.  of  lith¬ 
arge  in  powder,  and  2  or  3  pints  of  linseed  oil.  Tha 


344  MISCELLANEOUS  RECEIPTS. 

article  is  then  to  be  brushed  over  with  this  varnish,  and 
dried  in  the  sun. 

A  Cement  for  broken  Earthenware. 

Take  1  oz.  of  dry  cream  cheese  grated  fine,  and  an 
equal  quantity  of  quick-lime  mixed  well  together,  with 
°  oz.  of  skimmed  milk,  to  form  a  good  cement,  when 
he  rendering  of  the  joint  visible  is  of  no  consequence 
f  mixed  without  the  milk,  it  perhaps  might  be  strongei 
till. 

To  take  Mildew  out  of  Linen. 

Take  soap  'and  rub  it  well ;  then  scrape  some  fine 
chalk,  and  rub  that  also  in  the  linen ;  lay  it  on  the 
grass ;  as  it  dries  wet  it  a  little,  and  it  will  come  out  at 
twice. 

Soda  Water,  to  make. 

Take  20  grains  tartaric  acid,  25  grains  super-carbonate 
of  soda:  dissolve  a  lump  of  sugar,  on  which  you  have 
poured  a  drop  of  oil  of  lemon  in  two  wine-glass-lulls  of 
water:  add  the  tartaric  acid  :  stir  it  till-dissolved.  Then 
dissolve  the  carbonate  of  soda  in  the  like  quantity  of 
water,  and  pour  the  two  solutions  quickly  together,  and 
drink  them  olf  as  rapidly  as  possible. 

To  cure  six  Hams. 

Take  0  ozs.  of  salt-petre,  2  lbs.  lOozs.  of  fine  salt, 
4|  lbs.  of  brown  sugar  or  1  gallon  of  molasses.  Hub 
them  with  this  mixture  for  one  week  every  day ;  then 
put  them  into  a  strong  pickle  (salt  and  water)  for  one 
month  ;  then  smoke  them,  if  to  keep.  Your  pickle  will, 
fter  the  hams  are  taken  out,  be  excellent  for  beef. 

Elastic  Cement  for  Bells. 

Dissolve  in  good  brandy,  a  sufficient  quantity  of  isin¬ 
glass,  so  as  to  be  as  thick  as  molasses.  This  composition 
l  am  credibly  informed  answers  the  purpose  remarkably 
well. 


MISCELLANEOUS  RECEIPTS. 


345 


To  soften  Horn. 

Take  1  lb.  of  wood-ashes,  add  2  lbs.  of  quick-lime,  put 
them  into  a  quart  of  water,  let  the  whole  boil  until  re¬ 
duced  to  one-third, — then  dip  a  feather  into  it,  if  the 
plume  comes  off  on  drawing  it  out,  then  it  is  boiled 
enough  ;  when  it  is  settled  filter  it  off,  and  in  the  liquor 
then  strained  add  shavings  of  horn,  let  them  soak  for 
three  days,  then  rubbing  oil  on  your  hands  work  the  horn 
into  a  mass,  and  print  or  mould  it  into  whatever  shape 
you  want. 

Varnish  for  Harness. 

Take  i  lb.  of  Indian  rubber,  1  gallon  of  spirits  of  tur 
pentine,  dissolve  enough  to  make  it  into  a  jelly  by  keepim 
almost  new  milk  warm  :  then  take  equal  quantities  o^ 
good  linseed  oil  (in  a  hot  state)  and  the  above  mixture 
incorporate  them  well  on  a  slow  fire,  and  it  is  fit  for  use 

V arnish  for  fastening  the  leather  on  top  rollers  in 

Factories. 

Dissolve  2f  ozs.  of  gum-arabic  in  water,  and  add  so 
much  isinglass  dissolved  in  brandy  and  it  is  fit  for  use. 

The  manner  of  soldering  Ferrules  for  Tool-handles,  fyc. 

Take  your  ferrule,  lap  round  the  joining  a  small  piece 
of  brass-wire,  then  just  wet  the  ferrule,  scatter  on  the 
joining-ground,  borax,  put  it  on  the  end  of  a  wire,  hold  it 
in  the  fire  till  the  brass  fuses.  It  will  fill  up  the  joining, 
and  form  a  perfect  solder.  It  may  afterwards  be  turned 
in.  the  lathe. 

To  make  White-wash  that  will  not  rub  off. 

Mix  up  half  a  pail  full  of  lime  and  water,  ready  to  put 
on  the  wall ;  then  take  pint  of  flour,  mix  it  up  with 
water,  then  pour  on  it  boiling  water,  a  sufficient  quantity 
to  thicken  it ;  then  pour  it,  while  hot,  into  the  white¬ 
wash  ;  stir  all  well  together,  and  it  is  ready. 


346 


MISCELLANEOUS  RECEIPTS. 


An  improved  method  of  tempering  Gravers ,  when 

too  hard. 

Hating  heated  a  poker  red-hot,  hold  the  graver  upon 
it,  within  an  inch  of  the  point,  waving  it  to  and  fro,  till 
the  steel  changes  to  a  light  straw  colour ;  then,  having 
a  piece  of  steel  prepared  tor  the  purpose,  with  two  nicks 
filed  in  it,  one  the  shape  of  a  lozenge,  the  other  a  square 
graver  edge ;  when  heated  to  a  straw  colour,  put  the 
belly  of  the  graver  in  one  or  other  of  the  nicks,  as  the 
shape  may  be,  and  instead  of  plunging  it  into  water,  tal¬ 
low,  or  oil,  hammer  it  on  the  back-side  carefully,  till 
cold,  and  you  will  have  a  far  superior  tool,  if  rightly 
managed,  than  by  tempering  the  common  way.  This 
method  closes  up  the  pores  of  the  steel  when  heated, 
and  renders  it  more  compact ;  consequently,  does  not 
break.  It  would  be  well  lor  dentists  to  manage  tools  on 
this  principle,  for  good  service  and  utility. 

Easy  way  of  cleaning  the  Hands ,  for  Dyers ,  Col- 

ourers,  <$’C. 

Take  a  small  quantity  of  pot-ash  or  pearl-ash  in  your 
hand,  pour  into  it  a  small  quantity  of  water,  rub  it  well 
all  over  your  hands  with  a  little  sand,  then  wash  it  off, 
take  in  your  hand  a  small  quantity  of  chemic  (chloride 
of  lime,)  pour  a  little  water  into  it,  and  rub  it  well  on 
the  hands  in  a  semi-liquid  state ;  wash  the  hands  well  in 
water,  and  they  will  be  clean.  If  not  perfectly  clean, 

epcat  the  operation. 

Method  of  keeping  the  Hands  soft  and  pliable  in 
all  situations. 

Rub  the  hands  well  in  soap  till  a  lather  is  produced ; 
then  rub  on  a  sufficient  quantity  of  sand  to  let  the  soap 
and  water  predominate ;  after  well  rubbing,  wash  well 
in  warm  water.  Repeat  this  two  or  three  times  a  day, 
as  circumstances  may  require,  and  the  hands  will  be  kept 
perfectly  soft. 


Mi  '  ELLANEOUS  RECEIPTS. 


347 


Ink-Powder. 

Infuse  a  |  lb.  o  galls  powdered,  and  1^  ozs.  of  porne« 
granate  peels,  in  a  ,  gallon  of  soft  water  for  a  week,  in 
a  gentle  heat,  ano  then  strain  off  the  fluid  through  a 
cloth.  After  which  add  to  it  4  oz.  of  vitriol  dissolved  in 
a  pint  of  water,  ant  let  them  remain  for  a  day  or  two, 
preparing  in  the  m  .n  time  a  decoction  of  logwood,  by 
boiling  a  half  pounu  of  the  chips  in  a  half  gallon  of 
water,  till  one  third  oe  evaporated,  and  then  straining 
the  remaining  fluid  while  it  is  hot.  Mix  the  decoction 
and  the  solution  of  galls  and  vitriol  together,  and  add 
2|  ozs.  of  gum-arabic  or  the  whitest  of  gum-senegal, 
and  then  evaporate  the  mixture  over  a  common  fire  to 
1  quart,  when  the  remainder  must  be  put  into  a  proper 
vessel,  and  reduced  to  dryness,  by  placing  it  in  a  suf¬ 
ficiently  warm  place,  or  letting  it  hang  in  boiling  water. 
After  the  whole  of  the  liquid  is  evaporated,  the  residue 
must  be  well  powdered.  When  wanted  for  use,  all  that 
is  needed,  is  to  dissolve  the  powder  in  water. 

To  give  iron  a  temper  to  cut  porphyry. 

Make  your  iron  red-hot,  and  plunge  it  into  distilled 
water  from  nettles,  acanthus,  and  pilosella ;  or  in  the 
very  juice  pounded  out  from  these  plants. 

To  prevent  iron  from  rusting. 

Warm  your  iron  till  you  cannot  bear  your  hand  on  it 
without  burning  yourself.  Then  rub  it  with  new  and 
clean  white  wax.  Put  it  again  to  the  fire  till  it  has 
soaked  in  the  wax.  When  done,  rub  it  over  with  a  piece 
of  serge.  This  prevents  the  iron  from  rusting  after¬ 
wards. 

To  dye  in  Gold,  Silver  Medals,  or  laminas,  through  and 

through. 

Take  Glauber  salt,  dissolve  it  in  warm  water,  so  as  to 
form  a  saturated  solution.  In  this  solution  put  a  small 
proportionate  quantity  of  calx,  or  magister  of  gold.  Then 


348 


MISCELLANEOUS  RECEIPTS. 


put  and  digest  in  it,  silver  laminas  cut  small  and  thin, 
and  let  them  lay  24  hours  over  a  gentle  fire.  At  the  end 
of  fhis  term,  you  will  find  them  thoroughly  dyed  gold 
colour,  inside  and  out. 

An  oil ,  one  ounce  of  which  will  last  longer  than  one 
pound  of  any  other. 

Take  fresh  butter,  quick-lime,  crude  tartar,  and  com- 
>non  salt,  of  each  equal  parts,  which  you  pound  and  mix 
well  together.  Saturate  it  with  good  brandy,  and  distil 
it  in  a  retort  over  a  gradual  fire,  after  having  adapted 
the  receiver,  and  luted  'Well  the  joints.- 

To  make  Corks  for  bottles. 

Take  wax,  hog’s  lard,  and  turpentine  equal  quantities 
or  thereabouts.  Melt  altogether  and  stop  your  bottles 
with  it. 

An  oil  to  prevent  pictures  from  blackening.  It  may 

serve,  also,  to  make  cloth  to  carry  in  tl\e  pocket  against 

wet  weather. 

Put  nut  or  linseed  oil  into  a  phial,  and  set  it  in  the 
sun  to  purify  it.  When  it  has  deposited  its  dregs  at  the 
bottom,  decant  it  gently  into  another  clean  phial,  and  set 
it  again  in  the  sun  as  before.  Continue  so  doing  till  it 
drops  no  more  faeces  at  all.  And  with  that  oil,  you  make 
the  above  described  compositions. 

To  gild  on  Calf  and  Sheep  Skin. 

Wet  the  leather  with  the  white  of  eggs;  when  dry, 
rub  it  with  your  hand  and  a  little  olive  oil,  then  put  the 
gold  leaf  and  apply  the  hot  iron  to  it.  Whatever  the 
hot  iron  shall  not  have  touched  will  go  off  by  brushing. 

To  dye  Wood  Red. 

Take  chopped  brazil  wood,  and  boil  it  well  in  water 
strain  it  through  a  cloth.  Then  give  your  wood  two  or 
three  coats,  till  it  is  the  shade  wanted.  If  wanted  a 
deep  red,  boil  the  wood  in  water  impregnated  with  alum 


MISCELLANEOUS  RECEIPTS.  349 

and  quick-lime.  When  the  last  coat  is  dry,  burnish  it 
with  the  burnisher,  and  then  varnish. 

Another  method  to  dye  Wood  Red. 

Take  vermilion  and  Spanish  brown ;  make  them  thin: 
with  linseed  oil  and  turpentine.  Rub  it  on  with  a  cloth 
in  such  a  manner  as  to  show  the  grain  of  the  wood ;  when 
dry,  varnish.  The  proportion  of  vermilion  and  Spanish 
brown,  must  be  in  proportion  to  the  fineness  of  the  shade 
wanted. 

To  imitate  Ebony. 

Infuse  gall-nuts  in  vinegar,  wherein  you  have  soaked 
rusty  nails ;  then  rub  your  wood  with  this ;  let  it  dry, 
polish  and  burnish. 

To  produce  various  undulations  on  Wood. 

Slack  some  lime  in  chamber  ley.  Then  with  a  brush 
dipped  in  it,  form  your  undulations  on  the  wood  accord¬ 
ing  to  your  fancy.  And,  when  dry,  rub  it  well  with  a 
rind  of  pork. 

To  soften  Ivory. 

In  three  ounces  of  spirits  of  nitre,  and  fifteen  of  spring- 
water,  mixed  together,  put  your  ivory  a  soaking.  And 
in  3  or  4  days,  it  will  be  soft  so  as  to  obey  your  fingers. 

To  dye  Ivory  thus  softened. 

1.  Dissolve,  in  spirits  of  wine,  such  colours  as  you  want 
to  dye  your  ivory  with.  And  when  the  spirit  of  wine 
shall  be  sufficiently  tinged  with  the  colour  you  have  put 
in,  plunge  your  ivory  in  it,  and  leave  it  there  till  it  is 
sufficiently  penetrated  with  it,  and  dyed  inwardly.  Then 
give  that  ivory  what  form  you  please. 

2.  To  harden  it  afterwards,  wrap  it  up  in  a  sheet  of 
white  paper,  and  cover  it  with  decrepitated  common  salt, 
and  the  driest  you  can  make  it  to  be;  in  which  situation 
you  shall  leave  it  only  24  hours. 

30 


350 


MISCELLANEOUS  RECEIPTS. 


To  whiten  ivory ,  even  that  which  has  turned  a  brown 

yellow. 

1.  Slack  some  lime  in  water,  put  your  ivory  in  that 
water,  after  decanted  from  the  ground,  and  boil  it  till  it 
looks  quite  white. 

2.  To  polish  it  afterwards,  set  it  in  the  turner’s  wheel, 
and  after  having  worked  it,  take  rushes  and  pumice- 
stones,  subtile  powder  with  water,  and  rub  it  all  till  it 
looks  perfectly  smooth.  Next  to  that,  heat  it  b)r  turning 
it  against  a  piece  of  linen,  or  sheep-skin  leather,  and 
when  hot,  rub  it  over  with  a  little  whitening  diluted  in 
oil  of  olive ;  then  with  a  little  dry  whitening  alone,  and 
finally  with  a  piece  of  soft  white  rag.  When  all  this  is 
performed  as  directed,  the  ivory  will  look  remarkably 
white. 

To  whiten  Bones. 

Put  a  handful  of  bran  and  quick-lime  together,  in  a 
new  pipkin,  with  a  sufficient  quantity  of  water,  and  boil 
t.  In  this  put  the  bones,  and  boil  them  also  till  perfect¬ 
ly  freed  from  greasy  particles. 

To  petrify  Wood,  <^*c. 

Take  equal  quantities  of  gem-salt,  rock-alum,  white 
vinegar,  chalk,  and  pebbles  powder.  Mix  all  these  in¬ 
gredients  together:  there  will  happen  an  ebullition.  If, 
after  it  is  over,  you  throw  in  this  liquor  any  porous  mat 
ter,  and  leave  it  there  a  soaking  four  or  five  days,  they 
will  positively  turn  into  petrifactions. 

A  preparation  for  Tortoise-shell. 

Take  orpine,  quick-lime,  pearl-ashes,  and  aquafortis. 
Mix  well  altogether,  and  put  your  horn  or  tortoise-shell 
in  it  to  soak. 

To  dye  Bones  any  colour. 

Boil  the  bones  first  for  a  good  while ;  then  in  a  ley  of 
quick-lime  mixed  with  chamber  ley,  put  either  verdigris, 
or  red  or  blue  chalk  or  anv  other  ingredient  fit  to  pro- 


MISCELLANEOUS  RECEIPTS. 


351 


cure  the  colour  you  want  to  give  to  the  bones.  Lay  the 
bones  in  the  liquor,  and  boil  them,  they  will  be  perfectly 
dyed. 

To  write  on  Silver  ivith  a  black  which  ivill  never  go  off 

Take  burnt  lead,  and  pulverize  it.  Incorporate  it  next 
with  sulphur  and  vinegar,  to  the  consistency  of  a  paint¬ 
ing  colour,  and  write  with  it  on  any  silver  plate.  Let  it 
dry,  then  present  it  to  the  fire  so  as  to  heat  the  work  a 
little,  and  it  is  finished. 

To  restore  Wine  that  is  turned  sour  or  sharp. 

Fill  a  bag  with  leek-seed,  or  of  leaves  or  twisters  of 
vine,  and  put  either  of  them  to  infuse  in  the  cask. 

To  correct  a  bad  taste  and  sourness  in  Wine. 

Put  in  a  bag  the  root  of  wild  horse-radish  cut  in  bits. 
Let  it  down  in  the  wine,  and  leave  it  there  two  days : 
take  this  out,  and  pdt  another,  repeating  the  same  till 
the  wine  is  perfectly  restored.  Or  till  a  bag  with  wheat: 
it  will  have  the  same  effect. 

To  cure  those  who  are  too  much  addicted  to  drinking 

Wine. 

Put  in  a  sufficient  quantity  of  wine,  three  or  four 
large  eels,  which  leave  there  till  quite  dead.  Give  that 
wine  to  the  person  you  want  to  reform,  and  he  or  she 
will  be  so  much  disgusted  with  wine,  that  though  they 
formerly  made  use  of  it,  they  will  now  have  an  aversion 
to  it. 

To  increase  the  sharpness  and  strength  of  Vinegar. 

Boil  two  quarts  of  good  vinegar,  till  reduced  to  one ; 
then  put  it  in  a  vessel  and  set  it  in  the  sun  for  a  week. 
Now  mix  the  vinegar  with  six  times  its  quantity  of  bad 
rinegar  in  a  small  cask :  it  will  not  only  mend  it,  but 
aiake  it  strong  and  agreeable. 

To  make  Vinegar  with  water. 

Put  30  or  40  lbs.  of  wild  pears  in  a  large  tub,  where 
you  leave  them  three  days  to  ferment.  Then  pour  some 


352 


MISCELLANEOUS  RECEIPTS. 


water  over  them,  and  repeat  this  every  day  for  a  month 
at  the  end  of  which  it  will  make  very  good  vinegar 
the  goodness  of  which  may  be  increased  by  the  above 
method.  . 

A  dry  portable  Vinegar. 

WasIi  well  half  a  pound  of  white  tartar  with  warm 
water,  then  dry  it,  and  pulverize  as  fine  as  possible. 
Soak  that  powder  with  good  sharp  vinegar,  and  dry  i 
before  the  fire  or  in  the  sun.  Re-soak  it  as  before  wit 
vinegar,  and  dry  it  as  above,  repeating  this  operation  a 
dozen  of  times.  By  these  means  you  will  have  a  very 
good  and  sharp  powder,  which  turns  water  instantly  into 
vinegar.  It  is  very  convenient  to  carry  in  the  pocket, 
especially  when  travelling. 

How  to  extract  the  essential  oil  from  any  floicer. 

Take  any  flowers  you  like,  which  stratify  with  com¬ 
mon  sea-salt  in  a  clean  earthen  glazed  pot.  When  thus 
filled  to  the  top,  cover  it  well,  and  carry  it  to  the  cellar 
Forty  days  afterwards  put  a  crape  over  a  pan,  and  empty 
the  whole  to  strain  the  essence  from  the  flowers  by  pres¬ 
sure.  Bottle  that  essence  and  expose  it  4  or  5  weeks  in 
the  sun,  and  dew  of  the  evening  to  purify.  One  single 
drop  of  that  essence  is  enough  to  scent  a  whole  quart  of 
water. 

To  make  Mutton  Suet  Candles,  in  imitation  of  Wax. 

1.  Throw  quick-lime  in  melted  mutton  suet;  the  lime 
will  fall  to  the  bottom,  and  carry  along  with  it  all  the 
dirt  of  the  suet,  so  as  to  leave  it  as  pure  and  as  fine  as 
wax  itself. 

2.  Now  if  to  one  part  of  the  suet,  you  mix  three  of 
real  wax,  you  will  have  a  very  fine,  and  to  appearance 
a  real  wax  candle,  at  least  the  mixture  could  never  be 
discovered,  nor  even  in  the  moulding  way  for  ornaments, 


353 


« 

RECEIPTS  ON  DYEING. 


RECEIPTS.  ON  DYEING. 

General  remarks  on  Dyeing. 

Cleanliness  in  dyeing  is  very  essential.  The  vessel, 
and  the  articles  to  be  dyed,  must  be  ridded  of  grease  and 
dirt ;  as  grease  resists  the  colouring  particles,  and  dirt 
leaves  a  stain. 

Soft  water  should  always  be  used  for  dyeing.  Vessels 
used  for  dyeing  small  articles,  should  generally  be  wash 
hand  basons,  small  copper  and  tinned  pans,  and  suf¬ 
ficiently  large  that  the  dyeing  liquor  be  not  spilt  by  dip¬ 
ping  the  article  in  and  out  when  dyeing. 

The  quantity  of  liquor  generally  necessary  for  dyeing 
a  dress  of  muslin,  crape,  sarsnet,  cambric,  &c.  is  about 
three  quarts  ;  for  a  larger  dress  a  proportionable  quantity. 

The  dyeing  utensils  are  simple,  being  composed  of 
tubs,  kettles,  horse,  or  a  couple  of  lathed  benches,  for 
the  purpose  of  placing  the  goods  upon,  when  they  come 
from  the  dye.  The  horse  may  be  in  form  of  a  carpen¬ 
ters’  stool.  A  doll  which  is  used  for  beating  blpnkets, 
counterpanes,  &c.  in  the  tub  in  order  to  clean  them.  For 
this  doll  some  use  an  article  similar  to  a  pavior’s  mall,  but 
of  smaller  dimensions :  others  have  a  circular  piece  of 
wood  2  inches  thick,  in  which  4  legs  are  fastened,  on  the 
under  side,  and  in  the  centre  a  pretty  long  handle,  with 
a  cross  piece  put  through  it  to  work  it  with.  Against 
the  wall  or  a  post,  fasten  a  hook  or  pin  to  put  on  your 
skeins,  and  tvith  a  small  stick  wring  them  out.  In  fancy 
dyeing  the  various  shades  of  cambric,  a  winch  is  in  fre¬ 
quent  use. 

The  liquors  should  always  be  stirred  with  a  spoon,  rod, 
ot  any  thing  that  is  clean,  previous  to  the  article  being 
dipped  in  it,  to  cause  the  colouring  particles  to  be  equally 
diffused,  so  that  the  article  to  be  dyed  receives  its  colour 
uniformly,  and  it  is  also  necessary  that  the  article  be 
moved  in  and  out  quick,  and  opened  to  receive  the 
colour  more  evenlv. 

30* 


X 


354 


RECEIPTS  ON  DYEING. 


Colours  generally  look  much  darker  when  wet,  there, 
fore,  allowance  should  generally  be  made  for  drying, 
which  should  always  be  done  in  a  warm  room,  pinned  or 
tretched  to  a  line. 

(1.)  Aluming 

Is  a  preparation  necessary  for  some  colours  in  order  to 
receive  the  colouring  particles,  such  as  crimson,  scarlet, 
purple,  and  some  other  colours.  If  any  article  is  direct¬ 
ed  to  be  alumed,  be  careful  to  rid  it  well  of  the  soap¬ 
suds,  as  alum  turns  soap  to  grease.  W  hen  the  article  is 
put  in  the  alum  liquor,  it  is  to  be  well  dipped  in  and  out, 
and  opened,  to  receive  this  preparation  more  equally, 
for  an  hour,  or  all  night  if  circumstances  admit,  and  when 
alumed,  it  must  be  well  wrung  out,  and  rinsed  in  two 
waters,  and  then  dvcd,  the  sooner  the  better,  before  get¬ 
ting  dry.  Note.— The  aluming  of  silks  ought  to  be  done 
cold,  or  it  will  be  deprived  of  its  lustre. 

(2.)  Preparing  of  the  dye-liquors,  or  scalding  the  woods. 

Having  something  like  the  end  of  a  tub,  about  one 
foot  deep,  with  a  copper  bottom,  bored  full  of  holes 
about  a  quarter  of  an  inch  in  diameter;  lay  a  piece  of 
rather  coarse  sheeting  on  this,  lay  it  altogether  on  another 
tub  ;  fill  it  with  the  wood  to  be  scalded ;  then  having 
a  copper-boiler  full  of  boiling  water,  fill  the  tub  which 
contains  the  wood  with  boiling  water,  stir  it  during  the 
time  it  is  going  through ;  fill  it  up  again,  and  so  repeat 
the  operation  till  you  have  got  all  the  strength  from  the 
wood.  The  criterion  by  which  to  know  when  the 
strength  is  gone  from  the  wood,  is  the  paleness  of  the 
liquor  as  it  runs  through.  This  operation  is  considered 
superior  to  boiling  the  wood  in  a  copper-boiler,  especially 
for  the  ground-woods ;  but  either  way  will  answer.  The 
method  of  rendering  the  liquor  stronger,  of  course,  is  by 
evaporation,  in  a  copper-vessel,  with  a  constant  fire  un¬ 
der  it  The  chips  of  dye-woods  are  generally  superior 
to  the  ground-woods,  as  they  are  not  so  likely  to  be  adul¬ 
terated. 


RECEIPTS  ON  DYEING. 


355 


(3.)  Pink  on  Silk. 

After  aluming,  (see  receipt  No.  1.)  handle  the  goods 
„o  be  dyed  in  peach-wood  liquor,  till  the  colour  desired ; 
then  take  out  and  put  in  a  little  alum  liquor,  handle  the 
goods  a  little  longer,  take  out,  rinse  in  water,  and  finish. 
NoTe. — In  most  cases,  where  the  shade  is  not  dark 
enough,  the  operation  must  be  repeated. 

(4.)  Brown  on  Silk. 

Alum  your  silk  :  (see  No.  1.)  Then  take  one  part  of 
fustic  liquor,  and  three  parts  of  peachwood  liquor ;  han¬ 
dle  in  these  till  it  becomes  a  good  brown;  (a  little  log¬ 
wood  liquor  will  darken  your  shade,  if  required,)  hedge 
out,  and  put  in  a  little  alum-water ;  again  put  in  your 
goods,  handle  a  little  longer,  then  take  out,  drain,  rinse 
well,  and  finish.  Note.— By  varying  the  peachwood  and 
fustic,  various  shades  may  be  obtained. 

(5.)  Green  on  Silk. 

Take  green  ebony,  boil  it  in  water,  let  it  settle  ;  take 
the  clean  liquor  as  hot  as  you  can  bear  your  hands  in  it, 
handle  in  it  your  goods  till  of  a  bright  yellow ;  then  take 
water,  and  put  in  a  little  sulphate  of  indigo ;  handle  your 
goods  in  this  till  of  the  shade  wanted.  Note. — The 
ebony  may  previously  be  boiled  in  a  bag,  to  prevent  it 
from  sticking  to  the  silk. 

(6.)  Sulphate  of  Indigo. 

Take  3  lbs  of  vitriol,  1  lb.  of  ground  indigo ;  put  in  a 
little  at  a  time,  and  keep  stirring  till  all  dissolved.  Let 
stand  24  hours,  and  ready. 

(7.)  Blue  on  Silk. 

Indigo,  same  as  No.  5,  green ;  you  will  have  a  blue. 
Noxe. — The  silk  ought  to  be  boiled  in  white  soap  and 
water,  and  made  quite  white,  and  then  rinsed  in  luke¬ 
warm  water. 


356 


RECEIPTS  O?^  DYEING. 


(8.)  Black  on  Silk. 

Take  1  oz.  of  Milestone  of  vitriol,  2  oz.  of  copperas,  ^ 
oz.  of  nitrate  of  iron ;  mix  all  together  with  as  much 
water  as  will  do  one  piece ;  have  the  water  a  little 
warm  ;  hedge  in  this  six  times,  backward  and  forward, 
take  out,  rinse  in  water;  take  another  tub,  put  in  it  as 
much  logwood  liquor,  that  has  in  it  1  lb.  of  logwood,  1 
oz.  of  fustic  liquor  ;  hedge  in  this  liquor  with  a  sufficient 
quantity  of  water,  till  black  ;  wash  out,  and  finished. 
Note. — In  both  processes,  let  them  have  a  chance  to  air 
in  drying. 

(9.)  Blue  Black  on  Silk. 

First  run  through  a  mordant  of  nitrate  of  iron  and 
water,  then  run  through  pearl-ash  water,  then  through 
nitrate  of  iron  again  ;  then  put  them  through  logwood 
liquor,  with  a  little  bluestone  of  vitriol  dissolved  in  it.  If 
not  dark  enough,  repeat  the  operation. 

(10.)  Maroon  on  Silk. 

To  3  lbs.  of  silk,  take  ^  lb.  of  Cudbear,  put  it  in  wa¬ 
ter,  let  it  boil,  then  put  in  your  silk,  let  it  boil  a  few 
minutes,  keep  your  silk  well  handled,  take  out,  and  you 
will  have  a  good  handsome  colour.  To  change  the 
shade,  put  in  2  lbs.  of  common  salt :  operate  as  before: 
this  will  vary  the  shade.  To  vary  it  still  further,  take 
the  silk,  after  boiling  it  the  first  time  without  the  salt, 
handle  it  in  pearl-ash  water,  or  in  cream  of  tartar,  and 
you  will  have  a  handsome  blue. 

(11.)  Orange  on  Silk  or  Cotton. 

Take  1  lb.  of  silk,  1  oz.  of  arnotta,  2  oz.  of  pearl-ash, 
boil  them  well  together,  turn  in  vour  goods;  when  boiled 
10  minutes,  take  out,  wash,  and  finished. 

If  this  orange  is  dark,  handle  the  goods  at  hand-heat 

Note. — These  goods  must  be  well  washed  out  in  soap 
and  in  aluming  them,  you  may  use  a  little  sugar  of  lead 


RECEIPTS  ON  DYEING. 


357 


(12.)  Grey  on  Silk. 

For  a  silk  dress.  Take  4  or  6  oz.  of  fine  powdered 
galls,  pour  on  them  boiling  water,  handle  your  silk  in 
this  for  20  or  30  minutes;  in  another  form,  dissolve  a 
piece  of  green  copperas,  about  the  size  of  a  nut ;  handle 
your  silk  through  this,  and  it  will  be  a  grey,  more  or  less 
dark  according  to  the  quantity  of  drugs. 

(13.)  Slate  on  Silk. 

To  make  a  slate,  take  another  pan  of  warm  water 
and  about  a  tea-cup  full  of  logwood  liquor,  pretty  strong, 
and  a  piece  of  pearl-ash,  of  the  size  of  a  nut ;  take  the 
above  grey-coloured  goods,  and  handle  a  little  in  this 
liquor,  and  it  is  finished.  Note. — If  too  much  logwood 
is  used,  the  colour  will  be  too  dark. 

(14.)  Olive  on  Silk. 

By  adding  a  little  fustic  liquor  to  the  above  slate,  it  will 
form  an  olive :  it  may  be  necessary  to  run  them  through 
a  weak  pearl-ash  water  to  sadden  them.  Wash  in  two 
waters  for  the  above  three  colours.  They  will  keep 
their  colour  very  well. 

(15.)  Stone  colour  on  Silk. 

Take  the  coloured  grey  (see  receipt  No.  12.)  Add  a 
sufficient  quantity  of  purple  archil  to  the  grey  liquor. 
To  give  them  a  red  sandy  cast,  add  a  little  red  archil: 
simmer  the  silk  in  this  a  few  minutes.  Rinse  in  one  or 
two  cold  waters.  Dry  in  the  air.  The  red  archil  is 
made  from  purple  archil,  by  adding  a  small  quantity  cf 
vitriol  and  water,  which  will  redden  it. 

(16.)  To  dye  a  Silk  Dress  Brown. 

Take  8  oz.  of  sumach ;  4  oz.  of  logwood ;  8  oz.  of 
camwood  or  madder;  boil  these  drugs  in  water,  then 
cool  down  your  liquor ;  wet  out  your  silks ;  then  enter 
them;  handle  well;  wash  out  as  usual.  For  a  mulber¬ 
ry  cast,  add  as  much  purple  archil  as  may  be  necessary 


358 


RECEIPTS  ON  DYEING. 


(17.)  Drab  on  Silk . 

For  a  silk  dress.  Take  4  oz.  of  archil,  one  oz,  of 
madder;  enter  and  handle  the  goods;  this  may  be  sad¬ 
dened,  by  taking  oat  your  goods  and  dissolving  in  the 
liquor  a  piece  of  green  copperas,  the  size  of  a  nut 
again  handle  in  this  liquor;  or,  what  is  still  better,  in¬ 
stead  of  copperas,  use  a  little  pearl-ash  to  sadden  with. 

(18.)  j Dove  on  Silk. 

Take  Brazil  logwood  and  sumach;  vary  the  quantities 
as  you  want  your  shade ;  boil  them  in  water,  then  enter 
vour  goods,  handle  well,  and  sadden  with  green  copperas. 

(19.)  Yelloio  on  Silk. 

Boil  quercitron  barks  in  a  copper  pan  for  20  minutes, 
nny  quantity  you  please.  Dip  out  a  sufficient  quantity 
to  cover  your  silk,  in  another  copper  pan,  or  tinned  ves¬ 
sel,  into  which  add  a  small  quantity  of  muriate  of  tin ; 
pass  your  silks  first  through  warm  water,  and  wring  them 
out ;  then  put  them  into  this  pan  of  dye- water,  and  han¬ 
dle  them  with  a  clean  stick,  till  cold;  when  cold,  take 
out,  throw  out  your  liquor,  take  from  the  first  pan  as 
much  liquor  as  before,  handle  in  this  10  minutes,  then 
add  muriate  of  tin  according  to  shade  wanted.  Rinse 
out  in  its  own  liquor  and  dry  in  a  warm  room.  Annctto 
affords  an  orange  yellow  with  equal  quantities  of  pearl- 
ash,  and  gives  out  its  colour  to  silk  in  warm  water. 
Turmeric  gives  out  its  colour  in  a  similar  manner.  The 
roots  of  Barbary  afford  a  yellow  of  themselves,  when 
boiled  in  water. 

(20.)  Crimson  on  Silk. 

Take  Cudbear,  boil  it  in  water;  then  just  rinse  or 
handle  your  silks  in  it  for  a  few  minutes,  you  have  the 
shade  wanted.  Chamber  ley  or  any  alkaline  solution 
will  change  the  colour. 

(21.)  Flesh  Colour  on  Silk. 

Having  first  thoroughly  cleaned  your  silk  in  the  usual 
manner,  rinse  in  warm  water ;  then  handle  them  in  a 


RECEIPTS  ON  DYEING. 


359 

very  slight  water  of  alum  and  tartar,  so  slight  that  you 
could  hardly  taste  it.  Then  if  you  have  been  dyeing 
Pinks,  No.  3,  receipt,  take  some  of  the  old  liquor,  handle 
in  it  till  of  the  shade  wanted.  The  liquor  must  not  be 
too  strong,  or  the  shade  will  be  too  heavy. 

(22.)  Brown  on  Woollen  Cloth,  or  Clothes  of  any 

description. 

The  quantity  of  woods  to  be  regulated  according  to 
.'he  quantity  of  goods  to  be  dyed.  For  instance,  a  pair 
of  men’s  pantaloons,  being  first  well  cleaned  from  all 
grease:  take  1  lb.  of  red-wood,  hypernick,  or  peach- 
wood  ;  1  lb.  of  fustic,  put  them  in  a  copper  kettle,  boil 
them,  then  cool  down  so  as  to  bear  in  it  your  hand ;  then 
put  in  a  small  quantity  of  cream  of  tartar,  agitate  the 
water ;  then  enter  your  goods,  handle  them  till  they  come 
to  a  boil,  let  it  boil  5  or  10  minutes;  take  out  the  goods, 
put  in  a  strong  solution  made  of  4  oz.  of  copperas,  again 
cool  down,  re-enter  the  goods,  again  bring  them  to  a 
boil;  take  out,  rinse  well  in  water,  finished. 

This  process  makes  a  good  substantial  brown,  and 
might  be  varied  in  the  shade  by  varying  the  quantities 
of  woods  in  their  proportion,  also,  by  adding  a  little 
alum  in  the  saddening.  This  is  somewhat  of  an  olive 
cast. 

(23.)  A  Brown  on  the  Red  cast. 

Take  2  of  red-wood,  1  of  fustic,  proceed  in  every  re¬ 
spect  as  in  No.  22,  receipt,  the  desired  shade  will  be 
required.  The  quantity  of  dye-woods  may  be  regulated 
according  to  the  quantity  of  goods  to  be  dyed,  in  No.  22, 
also,  the  copperas  and  tartar.  On  woollen  of  course. 

(24.)  Olive  Brown. 

For  a  pair  of  pantaloons,  providing  they  weigh  3  lbs.; 
take  1  lb.  of  fustic,  1  oz.  of  logwood,  4  oz.  of  common 
Madder,  2  oz.  of  peachwood;  boil  them  up,  then  cool 
down  your  liquor,  enter  your  pantaloons,  bring  the  liquor 
to  a  boil,  let  it  boil  half  an  hour,  occasionally  turning 


360 


RECEIPTS  ON  DYEING < 


over;  take  out,  cool  down  your  liquor,  put  in  2  oz.  of 
dissolved  copperas,  handle  until  deep  enough.  For  wool 
Any  quantity  of  yarn  may  be  dyed  on  the  same  prin¬ 
ciple. 

•  (25.)  A  Brown  inclining  to  Snuff. 

Take  any  quantity  of  woollen  goods,  use  for  every 
lb.  li  or  2  lbs.  of  logwood  ;  first  put  your  logwood  into 
the  copper  vessel,  bring  it  to  a  boil ;  cool  down,  then 
enter  your  goods,  bring  them  to  boil,  half  an  hour  or 
longer,  if  a  large  quantity;  take  out,  wash  and  finished. 
Put,  however,  a  little  sumach,  about  2  oz.  to  the  lb.  ot 
logwood.  This  will  be  a  good  shade  of  brown.  To  alter 
this  shade,  put  into  your  liquor  a  proportionally  small 
quantity  of  alum  liquor,  again  enter  the  goods,  you  will 
fiave  a  good  handsome  shade  on  silk,  as  well  as  woollen. 

(20.)  A  Black  inclining  to  Purple  on  Wool  and  Silk . 

Take  4  lbs.  of  logwood,  1  lb.  of  sumach,  boil  them  in 
a  sufficient  quantity  of  water  ;  cool  down  with  water 
enough  to  dye  4  or  5  lbs.  of  silk  or  wool ;  enter  the  goods, 
bring  them  to  boil,  for  ten  minutes ;  take  out,  partly  cool 
down,  put  in  about  1  lb.  of  copperas ;  again  enter  your 
goods,  bring  them  to  a  boil,  take  out,  wash  and  finish. 
Chiefly  intended  for  wool. 

N.  B.  A  pair  of  pantaloons  or  any  other  article  which 
is  old,  would  not  need  to  be  so  particular  in  quantity  of 
dve-stufls,  nor  length  of  time.  It  will  also  answer  for 
cotton,  and  that  without  sumach,  if  the  sumach  is  not 
at  hand.  This  is  intended  chiefly  for  woollen. 

(27.)  A  Black  inclining  to  Brown  on  Silk  and  Woollen . 

Take  one  part  of  sumach,  one  of  logwood,  one  of  hv 
pernick  or  peachwood  ;  boil  the  dye-stulls,  cool  down 
put  in  the  silk  or  woollen  according  to  the  quantity  of 
your  dye-woods,  bring  them  to  a  boil,  for' ten  minutes 
take  out  the  goods,  cool  down ;  having  put  in  a  sufficient 
quantity  of  dissolved  copperas,  again  enter  the  goods 
bring  to  a  boil,  take  out,  wash  well  and  finish. 


RECEIPTS  ON  DYEING. 


361 

To  mix  the  copperas  with  alum  would  materially  alter 
the  shade,  if  a  variety  was  wanted.  This  is  chiefly  in 
tended  for  wool. 

(28.)  A  Jet  Black  on  Woollen  or  Woollen  Cloth. 

For  7  lbs.  of  wool  or  woollen  cloth,  take  3^  lbs.  of  log¬ 
wood,  f  lb.  of  sumach,  f-  lb.  of  fustic ;  boil  these  drugs 
in  a  sufficient  quantity  of  water  for  20  minutes,  coo 
down,  put  in  your  goods,  bring  to  a  boil  half  an  hour 
then  take  out,  cool  down  your  liquor ;  add  copperas  dis¬ 
solved  in  water  1|-  lbs.,  blue  stone  of  vitriol  2  oz. ;  again 
enter  your  goods,  bring  to  a  boil  15  minutes,  take  out, 
wash  well  in  cold  water,  and  finish. 

(29.)  Blue  Prussian  on  Woollen. 

Take  any  quantity  of  calcined  copperas,  dissolve  it  in 
warm  water,  strong,  put  in  your  goods,  keep  them  well 
handled  till  the  water  comes  nearly  to  a  boil,  still  handle 
15  minutes;  then  rinse  the  goods  in  cold  water;  get  up 
another  kettle  of  1  of  urine  to  3  of  water,  bring  the 
water  to  hand  heat ;  put  in  your  goods,  handle  half  an 
hour ;  again  rinse  in  cold  water ;  get  up  another  kettle 
of  water,  hand  heat,  and  for  each  lb.  of  goods  3  oz.  of 
prussiate  of  potash,  put  some  oil  of  vitriol  in  the  kettle, 
handle  the  goods  half  an  hour,  if  the  colour  looks  green, 
add  a  little  more  vitriol,  handle  half  an  hour  longer,  take 
out,  wash  in  cold  water,  and  finish. 

(30.)  Green  on  Wool. 

For  6  lbs.  of  yarn,  worsted,  or  cloth,  take  3  lbs.  of  fus¬ 
tic,  f  of  alum;  boil  them  in  a  kettle  10  minutes,  partly 
cool  down ;  then  put  in  a  small  tea-cup  full  of  sulphate 
of  indigo,  rake  it  well  up,  enter  yonr  goods,  bring  up  to 
a  boil,  keeping  the  goods  well  handled,  let  boil  20  min¬ 
utes,  (if  a  larger  quantity,  boil  longer  in  proportion,)  take 
out,  and  if  not  blue  enough,  add  a  little  more  sulphate 
of  indigo ;  handle  until  deep  enough.  Rinse  in  cold  wa 
ter,  and  finish. 

31 


RECEIPTS  ON  DYEING. 


362 

This  shade  may  be  altered  in  a  variety  of  ways,  by 
adding  a  little  camwood,  or  logwood,  in  the  first  boiling. 

(31.)  Lilac  on  Wool. 

Coil  up  any  quantity  of  archil,  according  to  the  quam 
tity  of  goods  you  want  to  dye;  cool  the  liquor  a  little, 
enter  the  goods,  handle  carefully,  until  the  shade  is  deep 
enough,  without  boiling  the  liquor,  take  out,  wash,  and 
finish.  1  lb.  of  archil  will  dye  4\  lbs  of  goods.  Silk  may 
be  dyed  in  the  same  way.  The  shades  may  be  altered 
by  soda,  pearl-ash,  wine,  or  common  salt,  adding  a  little, 
and  re-entering  the  goods  before  washing,  and  handling 
a  little  while  longer. 

(32.)  Drab  on  Woollen. 

For  about  15  lbs  of  woollen  goods,  take  £  lbs  of  weld, 
9  oz.  of  madder,  4  oz.  of  logwood,  3  oz.of  archil;  put  them 
in  water,  bring  them  to  a  boil  for  10  or  15  minutes,  cool 
down,  enter  the  goods,  boil  15  minutes,  wind  up;  put  in 
1  oz.  of  alum,  l£  oz.  of  copperas,  ground ;  boil  a  few 
minutes  longer,  during  which  time,  handle  well ;  take 
out,  wash,  and  finish.  The  above  receipt  may  serve  as 
a  standard  of  procedure  for  all  the  drab  shades,  which 
may  be  altered  at  pleasure,  that  can  be  produced ;  only 
varying  the  quantities  of  drugs,  in  some  cases  adding  ar¬ 
chil,  and  in  others,  a  little  sulphate  of  indigo.  Red  tartar 
and  camwood  may  also  be  used.  The  copperas  and 
alum  may  be  varied  in  quantity,  or  increased,  or  the 
alum  left  out ;  thus  varying  the  whole  round. 

(33.)  Red  on  Woollen. 

For  10  lbs.  of  woollen  goods.  Take  2  lbs.  of  alum, 
\  lb.  of  red  tartar;  boil  the  goods  in  this  1  hour;  (if  a 
larger  quantity  of  goods  boil  longer  time)  then  boil  up 
4^  lbs.  of  peachwood  in  clean  water,  cool  down  to  a 
scald,  put  in  2  oz.  of  No.  1,  tin  liquor,  enter  the  goods, 
handle  until  dark  enough,  and  finish.  The  goods  must 
not  be  washed  Dctween  the  1st  and  2d  operation. 


RECEIPTS  ON  DYEING. 


363 


(34.)  Slate  on  Woollen. 

For  10  lbs.  of  woollen  goods.  Take  10  lbs.  of  sumach, 
boil  it  up  10  minutes,  cool  down,  put  in  your  goods,  bring 
them  to  a  boil  a  few  minutes,  take  out,  put  in  4  lbs.  of 
copperas,  dissolve,  cool  down ;  re-enter  the  goods,  bring 
them  to  a  boil,  take  out,  wash  and  finish.  A  quantity 
of  iron  liquor,  such  as  the  calico-printers  use,  would  be 
preferable  to  copperas.  This  slate  may  be  varied  by 
varying  the  proportion  of  copperas  and  sumach ;  also,  by 
adding  a  little  peachwood,  or  any  other  red-wood ;  in  this 
case,  less  copperas  might  be  used. 

(35.)  Yellow  on  Wool. 

For  10  lbs.  of  wool.  Bring  a  kettle  of  water  to  a 
scald  or  180  degrees  of  heat,  put  in  4  lbs.  of  quercitron 
bark,  (do  not  allow  it  to  boil,  as  that  would  fetch  out  the 
tanning  and  dull  the  yellow)  1  lb.  of  alum,  6  oz.  of 
cream  of  tartar,  nearly  a  half  pint  of  No.  1,  tin  liquor; 
stir  up  the  liquor  well,  allow  it  to  settle  15  minutes; 
enter  the  goods,  keep  in  until  dark  enough. 

(36.)  Orange  on  Wool. 

First  dye  the  pattern  to  a  full  yellow.  Then  take  a 
clean  kettle  of  water,  when  a  little  warm,  put  in  for  the 
above  goods  2  lb.  of  madder,  peachwood,  mongeat,  or 
hypernick ;  mongeat  does  very  well :  put  in  your  goods, 
keep  them  well  handled,  bring  the  goods  to  a  boil,  let 
boil  till  dark  enough,  wash  and  finished. 

AARIOUS  SHADES  OF  FANCY  DYEING  ON 

COTTON. 

(37.)  For  any  quantity  of  Thread  in  Black. 

First  take  the  thread,  boil  it  in  sumach  and  water; 
then  let  it  be  immersed  in  lime-water,  cold  ;  then  in 
weak  copperas  water,  cold;  then  in  lime-water  again, 
cold;  then  in  logwood  liquor,  warm;  take  out,  put  some 
copperas  liquor  into  your  logwood  liquor,  again  put  in 
vour  goods,  handle  and  finish.  This  makes  a  first-rate 
black. 


364 


RECEIPTS  ON  DYEING. 


(38.)  Turmeric  yellow. 

Take  about  3  lbs.  of  turmeric,  put  it  in  a  small  tun 
for  the  purpose,  pour  on  it  a  tumbler  of  oil  of  vitriol,  stir 
it  well  up,  then  pour  on  it  hot  water,  about  two  gallons, 
stir  this  well  up ;  then  having  half  a  tub-full  of  water, 
boiling  hot  from  the  boiler,  pour  on  it  the  contents  of  the 
small  tub ;  enter  three  pieces,  30  yards  each,  give  them 
G  or  8  ends,  as  the  workmen  term  it,  fold  up ;  the  next 
process,  have  another  tub  of  water,  put  in  it  half  a  pale 
full  of  alum  liquor,  give  the  pieces  3  or  4  ends  in  this, 
take  out  and  finish.  Renew  with  the  same  quantity  for 
the  next  3  pieces,  and  so  proceed.  Note. — By  the  ends 
is  meant  rinsing  the  pieces  backward  and  forward  over 
the  wince  in  the  tub.  A  half  a  hogshead  will  answer 
the  purpose. 

It  will  be  understood  that  these  cotton  colours  are  in¬ 
tended  for  linings  or  cambrics.  It  will  also  be  nnderstood 
that  the  liquors  must  be  prepared  as  in  receipt.  No.  2, 
or  by  boiling  in  a  copper-cistern ;  the  former  is  most 
generally  adopted  for  this  kind  of  dyeing.  It  will  be 
necessary  to  have  a  number  of  tubs  for  the  different  li¬ 
quors;  and  in  dyeing  various  shades,  to  have  the  liquors 
prepared  in  readiness. 

(39.)  Green  on  Cotton. 

Take  as  much  hot  fustic  liquor  as  will  cover  3  pieces, 
in  which  is  put  a  very  little  lime  liquor,  put  it  in  a  tub, 
enter  your  goods,  give  them  5  ends,  hedge  them  out ; 
take  another  tub,  half  full  of  water  (cold),  put  into  it  a 
sufficient  quantity  of  blue-stone  of  vitriol  liquor,  to  set 
the  tub,  about  two  quarts,  enter  your  goods  in  this,  give 
,hem  five  ends,  hedge  out,  then  take  a  couple  of  pail- 
fulls  of  the  fustic  liquor,  renew  the  first  tub,  enter  3 
pieces  more,  and  so  proceed  as  at  first ;  then  renew  your 
blufc  vitriol  tub  with  half  the  quantity  of  liquor,  not 
taking  any  out,  and  proceed  as  at  first.  In  this  way  do 
as  many  the  first  and  second  time,  as  you  can  finish  that 
day;  then  comment. to  finish  them.  Take  half  a  tub 


RECEIPTS  ON  DYEING. 


365 


full  of  old  fustic  liquor  that  has  been  used  once,  and  put 
to  it  1|-  pail-fulls  of  logwood  liquor  ;  enter  your  pieces 
3  at  a  time,  give  them  five  ends,  and  finish.  Renew  with 
a  little  more  logwood  liquor,  enough  to  make  them  dark 
enough,  having  first  thrown  away  a  couple  of  pail-fulls 
from  the  tub,  and  renew  with  the  same  from  the  old  tub, 
and  so  proceeed  in  finishing. 

(40.)  Buff  on  Cotton. 

Take  as  much  hot  fustic  liquor  and  water,  as  will  half 
fill  a  tub,  enter  3  pieces,  give  them  5  ends,  hedge  out  ; 
take  another  tub  of  lime-water  cold,  enter  the  same 
pieces,  and  give  them  5  ends  in  this,  take  out,  and  in  a 
short  time  they  will  be  buffi  Renew  your  first  and 
second  tub,  and  proceed  as  at  first.  This  is  all  required 
for  buffi  • 

(41.)  Annetto  Orange  on  Cotton. 

Having  prepared  your  annetto  liquor  by  boiling  it  in 
a  copper  vessel  for  20  minutes ;  take  out  your  liquor,  put 
it  in  a  tub ;  partly  fill  your  boiler  with  water,  bring  it  to 
a  boil,  having  kept  in  the  boiler  the  sediment  of  the 
annetto,  make  it  strong  enough  with  annetto  liquor,  to 
the  shade  you  want  to  dye ;  enter  3  pieces  when  boiling, 
give  them  3  ends,  take  out ;  enter  them  into  cold  alum 
water,  give  them  4  ends,  take  out  and  finish.  Renew 
your  annetto  boiler  with  a  sufficient  quantity  of  annetto 
liquor,  and  proceed  as  before  ;  then  renew  your  alum 
tub,  proceed  as  before  in  the  2d  process.  This  finishes 
them. 

The  liquor  that  is  left  in  the  boiler  at  night,  will  do  to 
boil  the  annetto  in  the  next  day,  so  that  nothing  is  lost. 

(42.)  Red  on  Cotton. 

Take  3  pieces,  enter  them  into  a  tub  with  hot  red¬ 
wood,  or  peach-wood  liquor,  give  them  5  ends,  then  run 
them  into  your  wince ;  have  another  tub  called  the  spirit 
tub  close  by,  half  full  of  cold  water,  put  into  it  about  3 
tumblers  full  of  spirits;  then  run  the  pieces  from  tho 
31  * 


RECEIPTS  ON  DYEING. 


366 

other  wince  over  the  wince  of  the  spirit  tub,  give  them 
5  ends  in  the  spirit  tub,  then  wind  them  on  the  wince  of 
the  spirit  tub,  then  back  again  to  the  red  tub ;  give  them 
5  ends  without  having  renewed  the  tub,  they  are  finished. 

Throw  away  the  red  tub  liquor,  put  in  fresh  liquor, 
and  proceed  as  before ;  but  the  spirit  tub  must  be  re¬ 
newed  always;  even  at  night  it  may  be  left  in  a  tub,  and 
renewed  the  next  day. 

*  (43.)  Brown  on  Cotton. 

The  first  process  is  to  give  them  5  ends  in  hot  sumach 
liquor,  or  let  them  lay  all  night  in  the  large  tub,  same  as 
for  blacks;  then  give  them  5  ends  in  copperas,  hedge 
out,  give  them  5  ends  in  lime  tub ;  then  hedge  out,  lay 
them  one  side  till  you  get  enough  to  finish  that  day.  You 
next  renew  your  tubs  and  repeat  the  operation  as  before. 
Then  comes  the  finishing  part.  Make  up  a  tub  of  hot 
red- wood  liquor ;  enter  3  pieces,  give  them  5  ends,  put 
the  pieces  one  side  the  tub,  put  in  some  alum  liquor,  stir 
up,  give  them  5  ends  more,  hedge  out  and  finished. 

(44.)  Drab  on  Cotton. 

Take  half  a  tub  of  hot  sumach,  and  fustic  liquor ; 
more  fustic  than  sumach,  according  to  shade  wanted ; 
enter  3  pieces,  give  them  5  ends,  hedge  out ;  give  them 
5  ends  in  the  copperas  tub,  and  finished.  Renew  your 
tubs,  and  proceed  as  before.  The  copperas  tub  is  a  half 
a  tub  of  water,  with  a  couple  of  pail-fulls  of  copperas 
liquor  to  set  it  in  the  first  place ;  renewed  each  time. 

(45.)  Slate  on  Cotton. 

Make  up  a  tub  of  about  2  of  logwood  to  one  of  fustic 
liquor,  both  hot ;  enter  3  pieces,  give  them  5  ends,  hedge 
out ;  give  them  5  ends  in  copperas  liquor ;  have  it 
stronger  or  weaker  according  to  shade  wanted.  This 
finishes  them.  Renew  your  tubs,  and  proceed  as  before. 

(40.)  Purple  on  Cotton. 

Get  up  a  tub  of  hot  logwood  liquor,  enter  3  pieces 
give  them  5  ends,  hedge  out ;  enter  them  into  a  clean  alum 


RECEIPTS  ON  DYEING.  367 

ub,  give  them  5  ends,  hedge  out ;  get  up  another  tub  of 
logwood  liquor,  enter,  give  them  5  ends,  hedge  out ;  re 
uew  your  alum  tub,  give  them  5  ends  in  that,  and  finish 

(47.)  Black  on  Cotton . 

First  take  your  pieces  and  boil  {hem  in  sumach  liquor 
in  a  large  copper  vessel,  if  you  have  it,  that  will  hold  60 
or  70  pieces,  in  which  you  put  about  a  bushel  and  a 
half  of  sumach ;  let  them  stay  all  night  if  it  is  conve 
nient ;  take  out,  and  enter  them  into  the  lime-tub,  3  a 
a  time,  give  them  4  ends,  hedge  out ;  enter  them  into  the 
coppems  tub,  give  them  5  ends,  hedge  out ;  enter  them 
into  th«£  lime  again, -give  them  4  ends,  hedge  out ;  enter 
them  into  another  tub  with  tolerably  strong  logwood 
liquor,  give  them  5  ends ;  put  them  to  one  side  of  the 
tub,  put  m  enough  of  copperas  liquor  to  blacken  them, 
(about  a  couple  of  quarts,)  then  give  them  a  few  more 
ends,  and  they  are  finished.  With  this  process,  it  is  the 
same  as  with  the  greens.  After  sumaching,  liming,  cop¬ 
perassing,  and  second  lining  is  repeated,  till  you  get  as 
many  as  will  answer  you  to  finish  that  day,  the  tubs 
being  renewed  after  each  3  pieces :  then  comes  the  fin¬ 
ishing  ;  after  each  3  pieces,  the  logwood  and  copperas- 
liquor  is  thrown  away,  because  the  copperas  kills  the  log¬ 
wood,  and  so  renders  it  unfit  for  the  next  pieces.  It  is  _ 
frequently  the  case,  that  instead  of  the  first  process  of 
sumach  boiling,  they  collect  the  old  sumach,  and  fustic, 
and  logwood  liquor,  that  has  no  copperas  or  lime  in  it, 
into  a  large  tub,  and  all  the  pieces  that  are  spoiled  in  the 
other  colours,  they  throw  them  into  this  tub,  let  them  lay 
a  few  days  till  they  are  ready  to  dye  blacks,  and  this 
answers  instead  of  the  sumaching. 

For  the  foregoing  cotton  shades,  the  pieces  are  first 
taken  and  boiled  in  a  wood  or  copper  cistern,  as  circum¬ 
stances  may  be,  in  order  to  take  out  the  sizing,  and  pre¬ 
pare  them  to  receive  the  dye. 

(48.)  To  put  a  fine  gloss  on  Silk. 

Take  a  fair  white  potato,  cut  it  in  very  thin  slices, 
pour  on  it  boiling  water,  let  stand  till  rather  cool,  take 


RECEIPTS  ON  DYEING. 


368 

out  the  slices  of  potato,  run  your  silk  through  this  water 
squeeze  out,  smooth  while  damp,  and  you  will  have  a 
very  superior  gloss.  I  tried  this  on  black  silk,  and  found 
it  to  answer  well.  If  it  should  not  answer  on  lighter 
colours,  try  the  following  one.  If  a  quantity  of  silk,  of 
course  proportion  your  potatos. 

(49.)  Another  way 

Instead  of  a  potato,  use  a  small  quantity  of  isinglass, 
dissolved  in  water.  Use  it  the  same  as  the  above  in 
every  particular,  one  oz.  of  isinglass  will  answer  1  lb.  of 
silk. 

(50.)  Names  of  the  principal  Dyeing  Materials. 

Alum,  argal,  or  tartar,  green  copperas,  verdigris,  blue 
vitriol,  quercitron,  and  oak  bark,  mahogany-sawdust, 
with  acetate  of  alumine,  mordant  forms  a-  good  orange 
inclining  to  flesh  colour  ;  fenugreek,  logwood,  fustic,  Bra¬ 
zil  wood,  braziletto,  camwood,  barwood,  and  all  othei 
redwoods,  peachwood,  sumach,  galls,  weld,  madder  of 
various  kinds,  safflower,  savory,  green  ebony,  annatto, 
turmeric,  archil,  cudbear,  cochineal,  lac-dye,  indigo,  and 
tarzabonica  or  catecheu.  This  last  drug,  is  now  used 
extensively  in  colour-making  and  dyeing,  treated  with 
sal  ammoniac,  pearlash,  bicromatc  of  potash,  &c. 

(51.)  Pearlash  mordant,  with  walnut  husks,  produces 
a  nankeen. 

(52.)  No.  1,  Tin  Liquor. 

Take  2  quarts  muriatic  acid ;  killed  with  24  oz.  of 
granulated  tin.  This  will  answer  for  woollen,  or  cotton 

(53.)  No.  2,  Tin  Liquor  for  Yelloxes  on  Woollen. 

About  4  parts  of  muriatic  to  one  of  sulphuric,  killed 
with  granulated  tin.  This  will  answer  for  yellow  oo 
cotton  also. 

(54.)  Tin  Liquor  for  Pinks,  Scarlets,  Crimson,  SfC. 

1  Or  muriatic,  1  of  nitric  acids,  killed  with  tin. 


RECEIPTS  ON  DYEING. 


369 


(54.)  Tin  Liquor,  for  Scarlet,  Crimson,  <^-c.  on  Silk. 

Take  1  lb.  of  nitric,  and  1 ,1b.  of  muriatic  acids;  about 
i|  oz.  of  sal  ammoniac  ;  kill  with  granulated  tin. 

(55.)  The  manner  in  which  the  French  Madder  is 
marked  according  to  quality. 

First  quality  marked  E.  K.  F.  2d  Quality  E.  S.  F.  F. 
3d  Quality  S.  F.  F.  4th  Quality  S.  F. 

(56.)  To  set  an  Indigo  Vat  for  Cotton. 

Having  a  sufficiently  large  vat,  nearly  fill  it  with  water, 
put  in  30  lbs.  of  ground  indigo,  50  lbs.  of  copperas,  50 
lbs.  of  slacked  lime ;  occasionally  stir  it  up  for  two  days. 
When  perfectly  settled,  it  is  ready  for  use.  When  the 
vat  is  exhausted,  renew  with  4  lbs.  of  pearlash,  4  lbs.  of 
lime,  and  12  lbs.  of  copperas. 

(57.)  A  Blue  Vat  for  Silk  and  Woollen. 

Take  8  lbs.  of  indigo,  about  2  gallons  of  vinegar,  work 
it  in  the  mill  till  fine ;  if  this  is  not  convenient,  put  them 
on  a  slow  fire  for  24  hours,  till  dissolved ;  put  in  1  lb.  of 
madder,  mix  these  well,  and  put  them  into  a  vat  con¬ 
taining  100  gallons  of  urine,  stir  well  twice  a  day,  for 
1  week.  It  may  then  be  worked,  always  previously 
stirring  it.  This  vat  continues  to  be  good  till  exhausted. 
Nazarine  blues,  and  deep  purples,  may  be  managed  with 
this  vat  and  archil  dye,  taking  care  to  rinse  it  well  from 
one  to  the  other.  Archil  forms  a  dye  of  itself  without 
mordant,  on  silk  and  woollen,  when  boiled  in  water. 

(58.)  To  dye  Straws  Red. 

Boil  ground  Brazil-wood  in  a  ley  of  potash,  and  boil 
your  straws  in  it. 

(59.)  Blue  on  Straw. 

Take  a  sufficient  quantity  of  potash-ley,  1  lb.  of  litmus, 
or  lacmus-ground,  make  a  decoction  of,  and  then  put  iu 
the  straw,  and  boil  it. 

Y 


370 


RECEIPTS  ON  DYEING. 


(GO.)  Turkey-red  on  Leather. 

After  the  skin  has  been  properly  prepared  with 
sheep,  pig’s-dung,  &c.,  then  take  strong  alum-water,  and 
sponge  over  your  skin ;  when  dry,  boil  a  strong  gall 
liquor,  (it  cannot  be  too  strong ;)  then  boil  a  strong  Bra¬ 
zil-wood  liquor,  the  stronger  the  better;  take  a  sponge, 
dip  it  in  your  liquor,  and  sponge  over  your  skin  ;  repeat 
this,  till  it  comes  to  a  full  red  :  to  finish  your  skin,  take 
the  white  of  eggs  and  a  little  gum-dragon,  mix  the  two 
together  in  half  a  gill  of  water,  sponge  over  your  skin, 
and  when  dry,  polish  it  with  a  bottle,  or  piece  of  glass 
prepared  for  the  purpose. 

(61.)  Yellow  on  Leather. 

Infuse  quercitron  bark  in  vinegar,  in  which  boil  a 
little  alum,  and  brush  over  your  skins  with  the  infusion 
finish  same  as  the  red. 

(G2.)  Another  Yellow. 

Take  a  pint  of  whiskey,  4  oz.  of  turmeric ;  mix  them 
well  together;  when  settled,  sponge  your  skin  over,  and 
finish  it  the  same  way  as  the  red. 

(G3.)  Blue  on  Leather. 

For  each  skin,  take  1  oz.  of  indigo ;  put  it  into  boiling 
water,  and  let  it  stand  one  night ;  then  warm  it  a  little, 
and  with  a  brush,  smear  the  skin  twice  over,  finish  same 
as  the  red. 

(G4.)  Black  on  Leather. 

Put  your  skin  on  a  clean  board,  sponge  it  over  with 
gall  and  sumach  liquors  strong,  then  take  a  strong  log¬ 
wood  liquor,  sponge  it  over  3  or  4  times ;  then  take  a  lit¬ 
tle  copperas,  mix  it  in  the  logwood  liquor,  sponge  over 
rour  skin,  and  finish  it  same  as  the  red. 

(65.)  Different  Shades  on  Leather. 

The  pleasing  hues  of  yellow,  brown,  or  tan  colour,  are 
-eadily  imparted  to  leather  by  the  following  simple  pro- 


RECEIPTS  ON  DYEING. 


371 

cess.  Steep  saffron  in  boiling  water  for  a  number  of 
hours,  wet  a  sponge  or  soft  brush  in  the  liquor,  smear  the 
leather.  The  quantity  of  saffron,  as  well  as  of  water, 
will  of  course  depend  on  how  much  dye  may  be  wanted, 
and  their  relative  proportions  on  the  depth  of  colour  re¬ 
quired. 

(66.)  To  dye  Leather  purple. 

First  sponge  the  leather  with  alum  liquor  strong, 
then  with  logwood  liquor  strong,  or  mix  them  both  and 
boil  them,  and  sponge  with  the  liquor :  finish  same  as 
for  red. 


;  JT  iS’id  Aro  -  liUON 

\o  Tjtfn  HI  trffM  q-»3j3  wt 

. 

- 

-  .  <•  •  :TM  /.  .  . 

■  >•;•  vs  iwiMbnc 

jiooa  4*<wo>  ^otw/vHoaM 

.«  M-'»>  H»-  H  n::ilit  i  nir  •  *  *j  tv.; 

ilifer  i.  *il 
Ur; 

Am  k»1 

»*■  > 

*rfi»  >.  *  n 


biin  H)o<i 
a*  acflfi* 


’  xj»;j  ;io  .■  mu 


!T>r*r  3Jji  rvr*  ?> 


un 


v  !  <uiti  j**r 

.auuiita  wi  *m*kuxix 

,7cU  ■  ■  UV  <rj  Win  i}UJT 

jam  kimtoo  a  kk  tiu  t  a  *vi;t.jA*tAW  aarr 
..  ■*>•*  •  '  ■  ■* 

.  -  jmimOA 

vtf  IuVmb  ,*Vr*Tt'  *W 

‘  f  •  • 


A 


SUPPLEMENT 

TO  THE 

ARTIST’S  GUIDE 


AND 

MECHANIC’S  OWN  BOOK. 

WITH 

PRACTICAL  RULES  AND  TABLES 

for 

ENGINEERS,  MILLWRIGHTS,  MACHINE  MAKERS,  CARPENTERS, 
BRICKLAYERS,  SMITHS,  &c 

CONNECTED  WITH 

THE  STEAM  ENGINE,  WATER  WHEELS,  PUMPS,  AND 
MECHANICS  IN  GENERAL. 

ALSO, 

THE  STEAM  ENGINE  RENDERED  EASY, 

IN  A  SEPARATE  TREATISE,  WITH  PLATES. 

TO  WHICH  IS  ADDED, 

THE  MANAGER’S  ASSISTANT  IN  A  COTTON  MJLL, 

PROM  THE  RAW  MATERIAL  INTO  YARN  AND  CLOTH. 

ALSO, 

A  Corresponding  Scale  of  Beaume  and  Twedale’s  Hydromet  compared 
with  Specific  Gravity,  useful  for  Calico  Printers, 

Dyers,  Bleachers,  &c- 

BY  JAMES  PILKINGTON. 


BOSTON: 

SANBORN,  CARTER  AND  BAZIN. 
PORTLAND: 

SANBORN  &  CARTER. 

1856. 


.  .  .. 


.  .  .  *■ 


ti,;. 


y  \K  '  >  '  .■  ’ 


SIT  I  ft 

l  Lie  <•  'A.  'J&l  .L  ■  '  ■  UJ  L  ^ 

' 

« .  ,  ..  .  . l pfittS  •'•*'**, 

-  .  ■  ‘--if  rt:  .  J'-.yA 

!j  i*  (t4S«>  *?i  ?.*  £fffl  « *:  n  i' 

a* rii  -  ,, 

.  -  \  -v  -  :  ■  i  /  ..  ::  .  '  J"'V 

.  i 


a**.':  ;m.  m  arta  ^  u  inne  *H* 

i  .  ..  n  .  ■  .  ■  «-  >.  >*1 ' 

.  .  I  <T 

,i  .  *!  -  ■  sHitf 


■ 

r  ,  <  ■. 


_ _ 


041  <Vl  <x»i  •  .•  v*  :  u  ,v 


.vot n  t-  j  ir  :i  v.  al 


•  .0"  O -i 
L  #21^4$ 

1  i 


l ^ A5f  <  /-  ...:  ::u  i  <./"QS  i.v-  " 


STEAM  ENGINE. 


I  trust  I  shall  not  be  thought  impertinent,  and,  I  hope, 
not  partial,  in  recommending  one  of  the  latest,  and  I  may 
safely  say,  the  best  improvement  as  yet  known,  for  the 
economical  using  of  fuel;  itis  Mr.  Brunton’s  Fire  Regula¬ 
tor.  This  machine  feeds  the  fire  in  the  most  regular  man¬ 
ner,  and  nicely  proportions  the  quantity  of  coal  thrown 
upon  the  grate,  to  the  quantity  of  steam  required. 

Almost  the  whole  of  the  public  works  using  steam  en¬ 
gines  in  London,  have  this  Fire  Regulator  attached  to  their 
boilers.  And  the  accounts  kept  by  their  engineers,  of  the 
quantity  of  coal  consumed,  exhibit  a  saving  of  from  15  to 
25  per  cent,  produced  by  it.  But  the  regular  manner  of 
feeding  the  fire,  and,  consequently,  the  saving  of  fuel,  are 
not  the  only  advantages  derived  from  it.  There  is  no  re¬ 
gular  fireman  needed,  the  hopper  only  requires  to  be  filled 
with  coal  in  the  morning,  and  no  other  attendance  is  neces¬ 
sary  ;  also  the  supplementary  boiler,  which  is  attached  to 
the  large  boiler,  gives  an  additional  quantity  of  steam,  say 
from  2  to  6  horses,  in  proportion  to  the  size  of  the  engine, 
and  preserves  the  large  boiler  from  the  injurious  effects  of 
the  fire. 

These  advantages,  derived  from  this  Fire  Regulator  over 
the  usual  mode  of  feeding  the  fire  by  hand,  make  it  one  of 
die  most  useful  inventions  of  the  present  day,  and,  in  fact, 
a  steam  engine  is  not  complete  without  it. 

Since  the  last  edition  of  the  Compendium'was  published, 
Mr.  Brunton  has  added  a  further  improvement  to  his  Fire 


376 


STEAM  ENGINE. 


Regulator,  by  which  he  is  enabled  to  apply  it  immediately 
under  round  boilers  or  stills. — In  this  improved  state  it  is 
now  at  work  under  the  stills  of  Messrs.  Thomas  Smith  & 
Co.  Whitechapel  Distillery,  who  find  it  to  effect  a  very  con¬ 
siderable  saving  in  fuel  and  attendance. 

Boilers — are  of  various  forms,  but  the  most  general  is 
proportioned  as  follows,  viz.  width  1,  depth  1.1,  length  2.5 ; 
their  capacity  being,  for  the  most  part,  two  horse  power 
more  than  the  power  of  the  engine  for  which  they  are  in¬ 
tended.  These  are  the  proportions  of  the  wagon  boilers, 
but  the  cylindrical  boiler  with  a  flue  through  it,  is  now  fre¬ 
quently  used,  and  is  much  the  stronger  boiler  ;  it  is  also 
better  adapted  than  the  other  for  quickly  generating  steam, 
there  being  more  heating  surface  exposed  in  proportion  to 
the  volume  of  water  ;*  but  for  a  stationary  engine  that  is 
daily  employed,  the  elliptical  boiler  is  preferable;  it  con¬ 
tains  a  greater  body  of  water  than  the  cylindrical,  and 
though  the  steam  cannot  be  got  up  so  expeditiously,  yet, 
when  it  is  up,  it  can  be  kept  at  a  more  uniform  pressure, 
being  less  susceptible  of  any  variation  in  the  temperature 
of  the  furnace. 

Boulton  and  Watt  allow  25  cubic  feet  of  space  for  each 
horse  power,  some  of  the  other  engineers  allow  5  feet  of 
surface  of  water. 

Steam — arising  from  water  at  the  boiling  point,  is  equal 
to  the  pressure  of  the  atmosphere,  which  is,  in  round  num¬ 
bers,  15  libs  on  the  square  inch  ;  but  to  allow  for  a  con¬ 
stant  and  uniform  supply  of  steam  to  the  engine,  the  safety 
valve  of  the  boiler  is  loaded  with  3  libs  on  each  square 
inch. 

Where  boilers  are  in  good  order  and  sufficiently  strong, 
it  is  advisable  to  use  steam  at  a  pressure  of  10  libs  instead 
of  3  libs,  as  stated  above.  Steam  at  this  pressure  is,  con¬ 
sequently,  much  more  effective,  and  the  engine  performs  its 
work  with  greater  ease ;  but  to  use  steam  of  this  pressure, 

*  Common  pressure  boilers  ought  to  expose,  for  each  horse  power, 
12  square  feet  of  surface  to  the  heat  of  the  furnace — and  about  J  of  a 
square  foot  of  grate  surface  for  one  horse. 


STEAM  ENGINE. 


37? 


the  feed  pipe  of  the  boiler  requires  to  be  lengthened.  The 
following  Table  gives  the  vertical  heights  for  different 
pressures.  Beyond  15  libs  pressure  a  force  pump  is  gene* 
rally  used  instead  of  a  vertical  feed  pipe,  because  the  great 
length  would  not  only  be  inconvenient,  but  liable  to  acci¬ 
dent.  When  the  steam  is  at  this  pressure  it  can  be  used 
expansively,  that  is,  the  valve  can  be  shut  at  half  a  three 
quarter  stroke,  and  the  remainder  of  the  stroke  supplied 
by  the  expansion  of  the  steam  to  common  pressure;  tnis 
is  found  a  very  economical  mode  of  working  an  engine. 


TABLE. 


— Libs  Pressure 
on  the  Square  inch 
of  the  area  of 
Safety  V  alve. 

—Feet  of  Vertical  Height  of 
Feed  Pipe 
measured  from 

Water  Line  in  Boiler. 

5  libs 

13  feet. 

6  — 

15  — 

7  — 

18  — 

8  — 

20  — 

9  — 

23  — 

10  — 

25  — 

11  — 

28  — 

12  — 

30  — 

13  — 

33  — 

14  — 

35  — 

15  — 

38  — 

32* 


STEAM  ENGINE 


378 


The  following  Table  exhibits  the  expansive  force  oi 
steam,  expressing  the  degrees  of  heat  at  each  lit*  of  pre* 
sure  on  the  safety  valve. 


Decrees  of 
Heat. 

Libs  of 
Pressure. 

t - : - 

Decrees  of 
Heat. 

Libs  of 
Pressure. 

Degrees  of 
Heat. 

Libs  of 
Pressure. 

2120 

0 

268o 

24 

298° 

4S 

216 

1 

270 

25 

299 

49 

219 

2 

271 

26 

300 

50 

222 

3 

273 

27 

301 

51 

225 

4 

274 

28 

302 

52 

229 

5 

275 

29 

303 

53 

232 

6 

277 

30 

304 

54 

234 

7 

278 

31 

305 

55 

236 

8 

279' 

32 

306 

56 

239 

9 

281 

33 

307 

57 

241 

10 

282 

34 

308 

58 

244 

11 

283 

35 

309 

59 

246 

12 

285 

36 

310 

60 

248 

13 

286 

37 

311 

61 

250 

14 

287 

38 

312 

62 

252 

15 

288 

39 

313 

63 

254 

16 

289 

40 

313£ 

64 

256 

17 

290 

41 

314 

65 

258 

18 

291 

42 

315 

66 

260 

19 

293 

43 

316 

67 

261 

20 

294 

44 

317 

68 

263 

21 

295 

45 

318 

69 

265 

22 

296 

46 

319 

70 

267 

23 

297 

47 

320 

71 

By  the  following  Rule  the  quantity  of  steam  required  to 
raise  a  given  quantity  of  water  to  any  given  temperature 
is  found. 


STEAM  ENGINE. 


379 


Rule.  Multiply  the  water  to  be  warmed  by  the  differ¬ 
ence  of  temperature  between  the  cold  water  and  that  to 
which  it  is  to  be  raised,  for  a  dividend  ;  then  to  the  tempera¬ 
ture  of  the  steam  add  900  degrees,  and  from  that  sutn  take 
the  required  temperature  of  the  water :  this  last  remainder 
being  made  a  divisor  to  the  above  dividend,  the  quotient  will 
be  the  quantity  of  steam  in  the  same  terms  as  the  water. 


EXAMPLE. 


What  quantity  of  steam  at  212°  will  raise  100  gallons  of 
water  at  60°  up  to  212°? 


2i2o — 60°  X  100 
212°-j-900° — 212 


17  gallons  of  water  formed  into 


steam. 

Now,  steam  at  the  temperature  of  212°  is  1800  times  its 
bulk  in  water  ;  or  1  cubic  foot  of  steam,  when  its  elasticity 
is  equal  to  30  inches  of  mercury,  contains  1  cubic  inch  of 
water. — Therefore  17  gallons  of  water  converted  into  steam, 
occupies  a  space  of  4090-3-  cubic  feet,  having  a  pressure 
of  15  libs  on  the  square  inch. 

In  boiling  by  steam,  using  a  jacket  instead  of  blowing 
the  steam  into  the  water,  I  believe,  about  10.5  square  feet 
of  surface  are  allowed  for  each  horse  capacity  of  boiler — 
i.  e.  a  14  horse  boiler  will  boil  water  in  a  pan  set  in  a  jacket, 
exposing  a  surface  ofl0.5  X  14  =  147  square  feet. 


HorsePower. — Boulton  and  Watt  suppose  a  horse  able 
to  raise  32,000  libs  avoirdupois  1  foot  high  in  a  minute. 

Desaguliers  makes  it  27,500  I>bs. 

Smeaton  do.  22,916  do. 


It  is  common  in  calculating  the  power  of  engines,  to  sup¬ 
pose  a  horse  to  draw  200  libs  at  the  rate  of  2\  miles  in  an 
hour,  or  220  feet  per  minute,  with  a  continuance,  drawing 
the  weight  over  a  pulley — now,  200  X  220  =  44000,  i.  e. 
44000  libs  at  1  foot  per  minute,  or  1  lib  at  44000  feet  pet 
minute.  In  the  following  Table  32,000  is  used. 


One  horse  power  is  equal  to  raise 
l'bs - feet  high  per  minute. 


gallons  or 


380 


STEAM  ENGINE. 


Feet  nigh 
per  min. 

Ale 

Gallons. 

Libs  • 

Avoirdupois. 

Feet  High 
per  min. 

Ale 

Gallons. 

L'bs 

Avoirdupois. 

1 

3123 

32000 

20 

156 

1600 

2 

156H 

16000 

25 

125 

1280 

3 

1041 

10666 

30 

104 

1066 

4 

780 

8000 

35 

89 

914 

5 

624 

6400 

40 

78 

800 

6 

520 

5333 

45 

69 

711 

7 

446 

4571 

50 

62 

640 

8 

390 

4000 

55 

56 

582 

9 

347 

3555 

60 

52 

533 

10 

312 

3200 

65 

48 

492 

11 

284 

2909 

70 

44 

457 

12 

260 

2666 

75 

41 

426 

13 

240 

2461 

80 

39 

400 

14 

223 

2286 

85 

37 

376 

15 

208 

2133 

90 

34 

355 

16 

195 

2000 

95 

32 

337 

17 

183 

1882 

100 

31 

320 

18 

173 

1777 

110 

28 

291 

19 

164 

1684 

120 

26 

267 

Length  of  stroke. — The  stroke  of  an  engine  is 
equal  to  one  revolution  of  the  crank  shaft,  therefore  double 
the  length  of  the  cylinder.  When  stating  the  length  of 
stroke,  the  length  of  cylinder  is  only  given,  that  is,  an  en¬ 
gine  with  a  3  feet  stroke,  has  its  cylinder  3  feet  long,  be¬ 
sides  an  allowance  for  the  piston. 


The  following  Table  shows  the  length  of  stroke,  (or 
length  of  cylinder,)  and  the  number  of  feet  the  piston  tra¬ 
vels  in  a  minute,  according  to  the  number  of  strokes  the 
engine  makes  when  working  at  maximum. 

When  calculating  the  power  of  engines,  the  feet  per 
minute  are  generally  taken  at  220. 


STEAM  ENGINE. 


381 


Length  of 
Stroke. 

Numberof 

Strokes. 

Feet  per 
minute. 

Feet  2 

43 

172 

—  3 

32 

192 

—  4 

25 

200 

—  5 

21 

210 

—  6 

19 

228 

—  7 

17 

238 

—  8 

15 

240 

LzJL 

14 

250 

Cylinder.  When  an  engine  in  good  order  is  perform¬ 
ing  its  regular  work,  the  effective  pressure  may  be  taken 
at  8  libs  on  each  square  inch  of  the  surface  of  the  piston. 

In  a  former  edition  the  maximum  effective  pressure  was 
stated  at  10  libs,  but  few  engines  are  seldom  or  ever  rev 
quired  to  produce  this  work. 

To  calculate  the  power  of  an  Engine. 

Rule  1.  Multiply  the  area  of  cylinder  by  the  effective 
pressure  =  say  8  libs,  the  product  is  the  weight  the  engine 
can  raise.  Multiply  this  weight  by  the  number  of  feet  the 
piston  travels  in  one  minute,  which  will  givethe  momentum, 
or  weight,  the  engine  canlift  1  foot  high  per  minute  ;  divide 
this  momentum  by  a  horse  power,  as  previously  stated,  and 
the  quotient  will  be  the  number  cf  horse  power  the  engine 
is.equal  to. 

Rule  2.  25  inches  of  the  area  of  cylinder  is  equal  to 

one  horse  power,  the  velocity  of  the  engine  being  conse¬ 
quently  220  feet  per  minute. 


EXAMPLE  I. 

What  is  the  power  of  an  engine,  the  cylinder  being  42 

inches  diameter,  and  stroke  5  feet? 

422  X  .7894  X  10  X  210  . 

- - -  66. 12  horse  power. 

44000  r 


I 


332 


STEAM  ENGINE. 


EXAMPLE  II. 

What  size  of  cylinder  will  a  60  horse  power  engine  re- 
quire,  when  the  stroke  is  6  feet  ? 

44000  X  60 

— =  1158  inches,  area  of  cylinder. 

X  iU 

J\'ote.  To  find  the  power  to  lift  a  weight  at  any  velocity, 
multiply  the  weight  in  libs  by  the  velocity  in  feet,  and  di¬ 
vide  by  the  horse  power  ;  the  quotient  will  be  the  number 
of  horse  power  required. 

TABLE. 


When  the  effec¬ 
tive  pressure  on 
each  inch  of 
piston  is 


i  53  libs. 
48  — 

43 - 

38  — 
33  — 
28  — 
23  — 
18  — 
13  — 

8  — 


The  area  equal  to 
one  horse  power 
will  be 


3.7  inches. 

4.17  — 

4.65  — 

5.26  — 

6.06  — 

7.14  — 

8.7  — 

11.11  — 

15.46  — 

25.  — 


Examples  calculated  by  Rule  2d,  and  by  the  above  Table. 

1st.  What  diameter  is  the  cylinder  of  a  40  horse  eugiue, 
common  pressure? 

^  40  X  25 

-  — 5~ —  =  35.7,  say  35^-  inches  diameter. 

2d.  What  diameter  is  the  cylinder  of  a  40  horse  en 
gine,  effective  pressure  33  libs  on  the  square  inch  ? 

^40  X  6-06 

=  17.6,  say  17f  inches  diameter. 


.7854 


STEAM  ENGINE. 


383 


3d.  The  cylinder  of  an  engine  is  40  inches  diameter, 
and  the  effective  pressure  is  20  libs  on  the  square  inch. — 
What  is  the  power  of  the  engine  ? 

Area  of  40  =  1256.6  h-  10  =  125.6  horse  power. 

Steam  Ways. — The  induction  passages  ought  to  be  in 
area  one  twenty-fifth  part  of  the  area  of  cylinder. — Say,  if 
area  of  cylinder  be  25,  the  area  of  induction  passage  should 
be  1. — The  eduction  passage  ought  to  be  a  little  more  in 
area  than  the  induction,  say  one  twenty-fourth  part  of  the 
area  of  cylinder,  in  place  of  one  twenty-fifth. 

Air  Pump. — The  cubic  contents  of  the  air  pump  is  equal 
to  one-fourth  of  the  cubic  contents  of  cylinder,  or  when  the 
air  pump  is  half  the  length  of  the  stroke  of  the  engine,  its 
area  is  equal  to  half  the  area  of  cylinder. 

Condenser — is  generally  equal  in  capacity  to  the  air 
pump  ;  but  when  convenient  it  ought  to  be  more :  for  when 
large,  there  is  a  greater  space  of  vacuum,  aud  the  steam  is 
sooner  condensed. 

Cold  Water  Pump. — The  capacity  of  the  cold  water 
pump  depends  upon  the  temperature  of  the  water.  Many 
engines  return  their  water,  which  cannot  be  So  cold  as  water 
newly  drawn  from  a  river,  well,  &c. ;  but  when  water  is  at 
the  common  temperature,  each  horse  power  requires  nearly 

gallons  per  minute.*  Taking  this  quantity  as  a  standard, 
the  size  of  the  pump  is  easily  found  by  the  following  Rule, 
viz. — Multiply  the  number  of  horse  power  by  gallons, 
and  divide  by  the  number  of  strokes  per  minute:  this  will 
give  the  quantity  of  water  to  be  raised  each  stroke  of  pump. 
Multiply  this  quantity  by  231,  (the  number  of  cubic  inches 
in  a  gallon,)  and  divide  by  the  length  of  effective  stroke  of 
pump,  the  quotient  will  be  the  area. 

*  An  engine  will  work  with  a  less  supply  of  water,  say  5  gallons 
per  minute ;  but  when  water  can  be  had  without  a  considerable 
expense  of  power,  7J  gallons  is  preferable ;  because  an  abund¬ 
ance  of  water  keeps  the  condenser,  &.c.  cool,  and  thereby  produces 
a  better  vacuum. 


STEAM  ENGINE. 


384 


EXAMPLE. 


What  diameter  of  pump  is  requisite  for  a  20  horse  power 
steam  engine,  having  a  3  feet  stroke,  the  effective  stroke 
of  pump  to  be  15  inches  ? 


20  X  7}  =  150 
”32 


stroke. 


=  4.6875  gallons  the  pump  lifts  each 


4.6S75  X  231 
15 


=  72.1875  inches  area  of  pump. 


Hot  Water  Pump. — The  quantity  of  water  raised  at 
each  stroke  ought  to  be  equal  in  bulk  to  the  900th  part  of 
the  capacity  of  the  cylinder. 


example  i. 


What  quantity  of  feed  water  is  necessary  to  supply  the 
boiler  of  a  10  horse  engine,  common  pressure? 


25  X  10  X  220 

144 


=  382  cubic  feet  of  steam  used,  and 


the  water  contained  in  1  cubic  foot  of  steam  is  1  cubic 
inch  ;  so  that  382  cubic  inches  of  water,  or  1£  gallon,  is 
required  per  minute ;  the  pump,  however,  ought  to  be 
made  sufficiently  large  to  supply  2  gallons  per  minute,  to 
make  up  for  any  leakage  or  waste  of  steam. 


EXAMPLE  II. 


What  quantity  of  feed  water  is  necessary  to  supply  the 
boiler  of  a  10  horse  engine,  the  effective  pressure  30  libs? 
33libs  pressures  6.06  J  30,ibs  willbethem(!(iium  =6.6. 
28  libs  pressure  =  7.14  j 


6.6  X  10  X  220 
144 


=  101  cubic  feet  of  steam  equal  to  101 


cubic  inches,  or  -j^ths  nearly  of  a  gallon  of  water.  The 
pump  ought  to  supply  ^  gallon  per  minute. 


Proportions. — The  length  of  stroke  being  1,  the  length 


STEAM  ENGINE. 


385 


of  beam  to  centre  will  be  2,  the  length  of  crank  .5,  and 
the  length  of  connecting  rod  3. 


The  following  Table  shows  the  force  which  the  con¬ 
necting  rod  has  to  turn  round  the  crank  at  different  parts 
of  the  motion. 


Col. 


Col. 


Col. 


Col. 


Col. 


A. 


B. 


C. 


D. 


C. 


Decimal  proportions  of 
descent  of  the  piston, 
the  whole  descent  be¬ 
ing  1. 

Angle  between  the  con- 
nectingrod  and  crank. 

Effective  length  of  the 
lever  upon  which  the 
connecting  rod  acts, the 
whole  crank  being  1. 

Decimal  proportions  of 
half  a  revolution  of  the 
fly-wheel. 

Also  shows  the  force 
which  is  communicat¬ 
ed  to  the  fly-wheel,  ex¬ 
pressed  in  decimals, 
the  force  of  the  piston 
being  1. 


A 

B 

c 

D 

.0 

180° 

.0 

.0 

.05 

151! 

.46 

.12S 

.10 

141 

.62 

.158 

.15 

131! 

.74 

.228 

.2 

123! 

.830 

.271 

.25 

117f 

.892 

.308 

.3 

liof 

.94 

.342 

.35 

104 

.976 

.377 

.4 

97! 

.986 

.41 

.45 

91! 

1. 

.441 

.5 

85! 

1. 

.473 

.55 

so 

.986 

.507 

.6 

75 

.956 

.538 

.65 

69 

.92 

.572 

.7 

62! 

.88 

.607 

.75 

57! 

.824 

.642 

.8 

49 

.746 

.68 

.85 

42 

.66 

.723 

.9 

34 

.546 

.776 

.95 

23! 

.390 

.84 

.0 

0 

.000 

1.0 

F ly-Wheel— is  used  to  regulate  the  motion  of  the  en¬ 
gine,  and  to  bring  the  crank  past  its  centres.  The  rule 
for  finding  its  weight,  is,— Multiply  the  number  of  horses’ 
power  of  the  engine  by  2000,  and  divide  by  the  square  of 
the  velocity  of  the  circumference  of  the  wheel  per  second, 
the  quotient  will  be  the  weight  in  cwts. 

example. 

Required  the  weight  of  a  fly  w&eel  proper  for  an  engine 
33  g 


386 


STEAM  ENGINE. 


of  20  horse  power,  IS  feet  diameter,  and  making  22  rcvo* 
lutions  per  minute  ? 

IS  feet  diameter  =  56  feet  circumference,  X  22  revolu¬ 
tions  per  minute  =  1232  feet,  motion  per  minute  60  = 
20^-  feet,  motion  per  second ;  then  20^-2  =  420  the  divisor. 

20  horse  power  X  2000  =  40000  dividend. 

40000  .  ,  „  ,  , 

- =  90.4  cvvt.  weight  of  wheel. 

42  Of  ° 

Parallel  Motion.  The  radius  and  parallel  bars  are 
of  the  same  dimensions  ;  their  length  being  generally  one- 
fourth  of  the  length  of  the  beam  between  the  two  glands, 
or  one-half  the  distance  between  the  fulcrum  and  gland. 
Both  pairs  of  straps  are  the  same  length  between  the  cen¬ 
tres,  and  which  is  generally  three  inches  less  than  the  half 
of  the  length  of  stroke 

Governor,  or  Double  Pendulum. — If  the  revolutions 
be  the  same,  whatever  be  the  length  of  the  arms,  the  balls 
will  revolve  in  the  same  plane,  and  the  distance  of  that 
plane  from  the  point  of  suspension,  is  equal  to  the  length  of 
a  pendulum,  the  vibrations  of  which  will  be  double  the  revo¬ 
lutions  of  the  balls.  For  example  ;  suppose  the  distance 
between  the  point  of  suspension  and  plane  of  revolution  be 
36  inches,  the  vibrations  that  a  pendulum  of  36  inches  will 

375  .  .  62 

make  per  minute,  is  =  — —  =  62  vibrations,  and— =31 

V36  2 

revolutions  per  minute  the  balls  ought  to  make. 

For  the  sake  of  variety  in  the  steam  engine,  we  shall 
add  the  following  table  of  the  force  and  heat  of  steam. 
Also,  the  power  of  steam  engines,  and  the  method  of 
computing  it. 

The  force  of  Steam  and  the  heat  of  it. 

At  the  temperature  of  212  degrees  of  Fahrenheit’s 
Thermometer,  the  force  of  steam  from  water  is  just  equal 
to  the  pressure  of  the  atmosphere  ;  but  by  increasing  the 
heat,  effects  will  be  obtained,  which  are  detailed  in  the 
following  Table : 


STEAM  ENGINE. 


387 


a>  o  •—  o 

a 

bfi  rt~g  § 

a  &  3 


a> 


s>  cr 


_  ni 

eS-G 

•9r*t2J^3 

E  °  "  » 

O  “  O 
■B  «  S  J; 

«  i=  c«2 
n.g  o  o 
8  S  s' - 

S  Qj  (U 

rfi  .^Z 


'  5 
6 

7 

8 
9 

10 

15 

20 

25 

30 

35 

40 


'‘O 

O  0) 

.2  .2  2 

^  Ctf  . — < 

£  c  § 
«s  *3  <y 
G  2  oj 

„ 

u> 

<D  C3 

p.  0  >- 

O  -I) 

J2  & 

"S  cfl  2 

2  «J  ® 

g  t-  *r 

"  Sh  « 

•  of  >. 

t.  -O 


CU 


227| 

2301 

232| 

2351 

237j 

2391 


250 

2591 

267“ 

273 

278 

1282 


n 


A  H3  w  T3 
^  G  ^  ci 
cd  Jg  0)  g 
rv.  n  s 
^  IT  bo  &1 

^  CD  <D  W 
.G'-G  H3  <D 

-a  a) 

«  C  «  CJ 
ci  5  rt 
<d  g  •  —  o 

-=  S  o  _, 
'-S®  S“ 

£  £  2  o 

8^  -  7^ 
#  ®  ®  „ 

K «  m  t!  O 

GD-;-  <D  G  -w 

<d  Si  S  a* 

D-C  •£  dG  2h 

G  CD 

QJ  •♦-»  Vh  ^2 


5 

6 

7 

8 
9 

10 

15 

0 

25 

30 

35 

40 


^ * a 

S  rS  "S 

~  ^  V. 

G  M  o 

a-  <D 

3  fl  M 

>  2  (/3 

o'  ^ 

•'H  0>  P*  - 

£  G  „  i 

i  g-SJ 

r~!  o  r, 

H  d  ^  c 

8  ir£ 


By  small  additions  to  the  temperature,  an  expansive 
force  may  be  given  to  steam,  so  as  to  be  equal  to  400  times 
its  natural  bulk,  or  in  any  other  proportion,  provided  the 
vessels,  & c.  that  contain  it  be  strong  in  proportion. 

The  Power  of  Steam  Engines ,  and  the  Method  of  com¬ 
puting  it. 

In  computing  the  power  of  a  steam  engine,  three 
things  must  be  duly  observed.— 1.  The  width  or  diame¬ 
ter  ot  the  piston  or  cylinder.— 2.  The  length  of  the  stroke. 
3.  The  strength  of  the  steam.  It  is  supposed  that  the  pis¬ 
ton  does,  or  ought  to  travel  220  feet  per  minute. 

The  power  ot  an  engine  must  vary  according  to  the 
stiength  of  the  steam  ;  and  this  must  be  the  first  point  to 
be  decided.  This  pressure  is  fixed  at  different  ratios  by 
different  makers,  varying  from  7  to  12  lbs.  upon  the  square 
inch.  At  Soho,  they  commonly  fix  it  at  7  lbs.  and  Smea- 
ton  only  reckoned  7  lbs.  upon  every  circular  inch. 

Now  the  pressure  being  determined  by  the  weight  upon 
the  safety  valve,  here  is  the  most  correct  of  airmethods 
of  ascertaining  the  power. 

First.  Find  out  how  many  hogsheads  or  pounds  of 
water  the  engine  is  capable  of  raising  one  foot  high  in 
one  minute.  ° 

Secondly.  Divide  that  amount  by  the  supposed  ratios 
or  supposed  power  of  a  horse  to  raise  water  1  foot  high  in 
1  minute  of  time,  and  the  quotient  will  give  horse  powers 
of  the  engine.  • 


288 


STEAM  ENGINE. 


Rule.— 1 .  Find  the  area  of  the  piston  in  square  inches, 
by  squaring  the  diameter  and  multiplying  the  amount  by 
.7854,  and  the  product  will  be  the  correct  area.  Or  as  the 
decimal  .78  is  near  to  .75  or  -f  ;  for  a  ready  calculation  not 
exactly  correct,  square  the  diameter  and  take  f  of  that  sum, 
and  that  will  be  the  area,  nearly  ;  *of  the  diameter  of  the 
piston  multiplied  by  its  circumference,  and  that  divided  by  4 
will  give  its  area  in  square  inches. — 2.  The  area  of  the  pis¬ 
ton  in  square  inches  must  showthe  number  of  square  inches 
exposed  to  the  pressure  of  the  steam  ;  now  if  we  multiply 
this  area  by  the  pressure  upon  every  square  inch,  we  shall 
have  the  whole  pressure  upon  the  piston,  or  the  weight 
which  the  engine  is  capable  of  raising,  and  if  the  piston 
travel  220  feet  per  minute,  that  amount  multiplied  by  220 
must  give  the  weight  of  water  that  the  engine  is  capable  of 
lifting  1  foot  high  in  one  minute. — 3.  Messrs.  Boulton  and 
Watt  suppose  a  horse  able  to  raise  32000  lbs.  avoirdupois, 
1  foot  in  a  minute.  Dr.  Desaguliers  makes  it  27500  lbs. 
Mr.  Smeaton  only  22916.  Divide  the  number  of  lbs. 
that  an  engine  of  one  horse  power  can  raise  1  foot  high 
in  1  minute,  and  the  quotient  will  give  the  horse  powers. 

EXAMTLE. 

What  is  the  power  of  a  steam  engine,  the  cylinder  of 
which  is  24  inches,  which  makes  22  double  strokes  in  a 
minute,  each  stroke  being  5  feet  long,  and  the  force  of  the 
steam  equal  to  12  lbs.  avoirdupois  upon  every  square  inch? 

24  inches  452.4  square  inches. 

24  12  lbs.  per  square  inch. 

96  5428.8  the  whole  pressure 

upon  the  piston. 

48 


576 

.7854 


452.3904  area,  nearly  452.4  square  inches. 


WATER  WHEEL. 


389 


Tho  engine  makes  22  double  strokes,  each  5  feet  in  a 
minute  =  220  feet,  then  5428.8  lbs.  multiplied  by 

220  feet  travelled  per  minute 

‘will  give  1 19436  lbs.  raised  1  foot  high  in  1 

minute. 

This  divided  by  the  standard  of  each  engineer’s  calcula* 
tion  for  a  horse’s  power,  and  the  quotients  will  give  of 
Boulton  and  Watt’s  37  horse  power. 

Desagulier’s  43  do.  do. 

Smeaton’s  52  do.  do. 


WATER  WHEEL. 

Water.  ( Hydrostatics .) 

Hydrostatics  is  the  science  which  treats  of  the  pressure, 
or  weight,  and  equilibrium  of  water,  and  other  fluids,  espe¬ 
cially  those  that  are  non-elastic. 

Note  1.  The  pressure  of  water  at  any  depth,  is  as  its 
depth ;  for  the  pressure  is  as  the  weight,  and  the  weight  is 
as  the  height. 

Note  2.  The  pressure  of  water  on  a  surface  any  how 
immersed  in  it,  either  perpendicular,  horizontal  or  oblique, 
is  equal  to  the  weight  of  a  column  of  water,  the  base  being 
equal  to  the  surface  pressed,  and  the  altitude  equal  to  the 
depth  of  the  centre  of  gravity,  of  the  surface  'pressed ,  be- 
bw  the  top  or  surface  of  the  fluid. 

PROBLEM  I. 

In  a  vessel  filled  with  water,  the  sides  of  which  are  up 
right  and  parallel  to  each  other,  having  the  top  of  the  same 
dimensions  as  the  bottom,  the  pressure  exerted  against  the 
bottom,  will  be  equal  to  the  area  of  the  bottom  multiplied 
by  the  depth  of  water. 

33* 


390 


WATER  WHEEL. 


EXAMPLE. 

A  vessel  3  feet  square  and  7  feet  deep,  is  filled  with  wa¬ 
ter  ;  what  pressure  does  the  bottom  support? 

32  X  7  X  1000 

- — -  =  3937^-  libs  avoirdupois. 

16 

PROBLEM  II. 

A  side  of  any  vessel  sustains  a  pressure  equal  to  tne  area 
of  the  side  multiplied  by  half  the  depth,  therefore  the  sides 
and  bottom  of  a  cubical  vessel  sustains  a  pressure  equal  to 
three  times  the  weight  of  water  in  the  vessel. 


EXAMPLE  I. 


The  gate  of  a  sluice  is  12  feet  deep  and  20  feet  broad; 
what  is  the  pressure  of  water  against  it  ? 


20  X  12  X  6  X  1000 
16 


=  90000  =  40f  tons  nearly. 


From  Note  2d. — The  pressure  exerted  upon  the  side  of 
a  vessel,  of  whatever  shape  it  may  be,  is  as  the  area  of  the 
side  and  centre  of  gravity  below  the  surface  of  water. 


EXAMPLE  II. 


What  pressure  will  a  board  sustain,  placed  diagonally 
through  a  vessel,  the  side  of  which  is  9  feet  deep,  and 
bottom  12  feet  by  9  feet? 

V  12 2  4“S}2=15  feet,  the  length  of  diagonal  board. 

15  X  9  X  X  1000 
- - =  37969  libs  nearly*. 


Though  the  diagonal  board  bisects  the  vessel,  yet  it  sus¬ 
tains  more  than  the  half  of  the  pressure  in  the  bottom,  for 
the  area  of  bottom  is  12  X  9,  and  the  half  of  the  pressure 
is  half  60759  =  30375. 

The  bottom  of  a  conical  or  pyramidical  vessel  sustains  a 
pressure  equal  to  the  area  of  the  bottom  and  depth  of  water, 
consequently,  the  excess  of  pressure  is  three  times  the 
weight  of  water  in  the  vessel. 


WATER  WHEEL. 


391 


Water.  (Hydraulics,) 

Hydraulics  is  that  science  which  treats  of  fluids  consider¬ 
ed  as  in  motion,  it  therefore  embraces  the  phenomena  exhi¬ 
bited  by  water  issuing  from  orifices  in  reservoirs,  projected 
obliquely,  or  perpendicularly,  in  Jet-d'eaux,  moving  in 
pipes,  canals,  and  rivers,  oscillating  in  waves,  or  oppos¬ 
ing  a  resistance  to  the  progress  of  solid  bodies. 

It  would  be  needless  here  to  go  into  the  minutiae  of  hy¬ 
draulics,  particularly  when  the  theory  and  practice  do  not 
agree.  It  is  only  the  general  laws,  deduced  from  experi¬ 
ment,  that  can  be  safely  employed  in  the  various  opera¬ 
tions  of  hydraulic  architecture. 

Mr.  Banks,  in  his  Treatise  on  Mills,  after  enumerating 
a  number  of  experiments  on  the  velocity  of  flowing  water, 
by  several  philosophers,  as  well  as  his  own,  takes  from 
thence  the  following  simple  rule,  which  is  as  near  the 
truth  as  any  that  have  been  stated  by  other  experimentalists. 

Rule.  Measure  the  depth  (of  a  vessel,  &c.)  in  feet, 
extract  the  square  root  of  that  depth,  and  multiply  it  by  5.4, 
which  gives  the  velocity  in  feet  per  second;  this  mul¬ 
tiplied  by  the  area  of  the  orifice  in  feet,  gives  the  number 
of  cubic  feet  which  flows  out  in  one  second. 

'  EXAMPLE. 

Let  a  sluice  be  10  feet  below  the  surface  of  the  water, 
its  length  4  feet,  and  open  7  inches;  required  the  quanti¬ 
ty  of  water  expended  in  one  second  ? 

VI 0  =  3.162  X  5.4  —  17.0748  feet  velocity. 

4X7 

— — - =  2 1  feet  X  17.0748  =  39.84  cubic  feet  of 

X  A 

water  per  second. 

If  the  area  of  the  orifice  is  great  compared  with  the 
head,  take  the  medium  depth,  and  two-thirds  of  the  velo¬ 
city  from  that  depth,  for  the  velocity. 

Given  the  perpendicular  depth  of  the  orifice  2  feet,  its 
horizontal  length  4  feet,  and  its  top  1  foot  below  the  sur¬ 
face  of  water.  To  find  the  quantity  discharged  in  one 
second : 


392 


WATER  WHEEL. 


The  medium  depth  is  =  1.5  X  5.4  =  8.10 — \  = 
6.40  X  8  =  43.20  cubic  feet.* 

The  quantity  of  water  discharged  through  slits,  or  notches, 
cut  in  the  side  of  a  vessel  or  dam,  and  open  at  the  top,  will 
be  found  by  multiplying  the  velocity  at  the  bottom  by  the 
depth,  and  taking  J-  of  the  product  for  the  area;  which 
again  multiplied  by  the  breadth  of  the  slit,  or  notch,  gives 
the  quantity  of  cubic  feet  discharged  in  a  given  time. 

EXAMPLE. 

Let  the  depth  be  5  inches,  and  the  breadth  6  inches ;  re¬ 
quired  the  quantity  run  out  in  40  seconds  1 

The  depth  is  .4166  of  a  foot. 

The  breadth  is  .5  of  a  foot. 

V  .4166  =  .6455  X  5.4  X  f  =  2.3238  X  -4166  = 
96825  X  *5  =  .48412  feet  per  second. 

Then  .48412  X  46.  =  22.269  cubic  feet  in  46  seconds. 

There  are  two  kinds  of  water  wheels,  undershot  and 
overshot.  Undershot  when  the  water  strikes  the  wheel  at 
or  below  the  centre.  Overshot,  when  the  water  falls  upon 
the  wheel  above  the  centre. 

The  effect  produced  by  an  undershot  wheel,  is  from  the 
impetus  of  the  water.  The  effect  produced  by  an  overshot 
wheel,  is  from  the  gravity  or  weight  of  the  water. 

Of  an  undershot  wheel  the  power  is  to  the  effect  as  3  :  1. 
— Of  an  overshot  wheel,  the  power  is  to  the  effect  as  3  :  2 — 
which  is  double  the  effect  of  an  undershot  wheel. 

•  The  square  root  of  the  depth  is  not  taken  in  this  example,  but  when 
the  depth  is  considerable,  it  ought  to  be  taken. 


WATER  WHEEL. 


393 


The  following  is  an  Abridgment  of  Smeaton  on  Water  Wheels, 

UNDERSHOT. 


Velocity  of  water  in  1"  =V 

Weight  of  1  cub.  in.  of  water  =W 
Area  of  sluice  —A 

Quantity  of  water  =Q, 

Power  of  the  water  to  } 
produce  mechanical  >  =P 

effect  A 


V.  A.=  Q  in  one  second. 

QW.V  =  P  ;  Power  to 
mechanical  effect. 


produce 


POWER  and  effect  of  maximum. 


Velocity  of  wheel  in  1"  ==  v 

Effective  velocity  of  water  =  E  -,T  „ 

Effect  produced  by  the  )  _  V  —  v  =  E 

wheel  i  ~  e 

Weight  raised  =  w  wv  =  e 

Velocity  of  weight  raised  =v 


P  :  e  :  :  10  :  3.62, 
or  3  :  1 

V  :  v  :  :  10  :  3.5, 
or  5  :  2. 


OVERSHOT. 


Descent  of  water  including  head 
and  diameter  of  wheel* 

The  weight  of  water  expended 
in  one  second 


J=D 

w 


D.W  =  P. 


Power  of  the  water  is  =  D.W 
=  P 

Effect  of  the  wheel  is  =  wv  =  e 


POWER  AND  EFFECT  AT  MAXIMUM. 

P  :  e  :  :  10  :  6  6,  or  3  :  2  nearly. 
Double  that  of  an  undershot. 


The  velocity  of  maximum  is  =  3  feet  in  one  second. 

Since  the  effect  of  the  overshot  is  double  that  of  the  un¬ 
dershot,  it  follows  that  the  higher  the  wheel  is  in  proportion 
to  the  whole  descent,  the  greater  will  be  the  effect. 

The  maximum  load  for  an  overshot  wheel,  is  that  which 
reduces  the  circumference  of  the  wheel  to  its  proper  velo¬ 
city,  _=  3  feet  in  1  second  ;  and  this  will  be  known,  by  di¬ 
viding  the  effect  it  ought  to  produce  in  a  given  time,  by  the 
space  intended  to  be  described  by  the  circumference  of  the 


*  By  Head  is  understood  the  distance  between  the  orifice  and  the  part  of  th« 
wheel  on  which  the  water  falls.  The  fall  is  Uie  perpendicular  height  from  tho 
bottom  of  the  wheel  to  the  orifice  " 


394 


WATER  WHEEL. 


wheel  in  the  same  time;  the  quotient  will  be  the  resistance 
overcome  at  the  circumference  of  the  wheel,  and  is  equal 
to  the  load  required,  the  friction  and  resistance  of  the  ma¬ 
chinery  included. 

The  following  is  an  extract  from  Banks  on  Mills ,  p.  152. 

“  The  effect  produced  by  a  given  stream  in  falling 
through  a  given  space,  if  compared  with  a  weight,  will  be 
directly  as  that  space  ;  but  if  we  measure  it  by  the  velo¬ 
city  communicated  to  the  wheel,  it  will  be  as  the  square 
root  of  the  space  descended  through,  agreeably  to  the  laws 
of  falling  bodies. 

“  Experiment  lv  A  given  stream  is  applied  to  a  wheel 
at  the  centre  ;  the  revolutions  per  minute  are  38.5 

“  Ex.  2.  The  same  stream  applied  at  the  top,  turns  the 
same  wheel  57  times  in  a  minute. 

«  If  in  the  first  experiment  the  fall  is  called  1,  in  the  s& 
cond  it  will  be  2  :  then  VI  :  V2  :  :  38.5  :  54.4,  which  are 
in  the  same  ratio  as  the  square  roots  of  the  spaces  fallen 
through,  and  near  the  observed  velocity .. 

“  In  the  following  experiments  a  fly  is  connected  with 
the  water  wheel. 

“  Ex.  3.  The  water  is  applied  at  the  centre,  the  wheel 
revolves  13.03  times  in  one  minute. 

“  Ex.  4.  The  water  is  applied  at  the  vertex  of  the  wheel, 
and  it  revolves  18.2  times  per  minute. 

“  As  13.03  :  18.2  :  :  VI  :  V2  nearly. 

«  From  the  above  we  infer,  that  the  circumferences  of 
wheels  of  different  sizes  may  move  with  velocities  which  are 
as  the  square  roots  of  their  diameters  without  disadvantage, 
compared  one  with  another,  the  water  in  all  being  applied 
at  the  top  of  the  wheel ;  for  the  velocity  of  falling  water  at 
the  bottom  or  end  of  the  fall  is  as  the  time,  or  as  the  square 
root  of  the  space  fallen  through ;  for  example,  let  the  fall 
be  4  feet,  then,  As  VI 6  :  1"  :  :  V4  :  the  time  of  falling 

through  4  feet : — Again,  let  the  fall  be  9  feet,  then,  V16  : 
1"  :  :  V9  :  and  so  for  any  other  space,  as  in  the  follow¬ 

ing  Table,  where  it  appears  that  water  will  fall  through  one 
foot  in  a  quarter  of  a  second,  through  4  feet  in  half  a  se¬ 
cond,  through  9  feet  in  3  quarters  of  a  second,  and  through 
16  feet  in  one  second.  And  if  a  wheel  4  feet  in  diameter 


WATER  WHEEL 


395 


moved  as  fast  as  the  water,  it  could  not  revolve  in  less  than 
1.5  second,  neither  could  a  wheel  of  16  feet  diameter  re¬ 
volve  in  less  than  three  seconds ;  but  though  it  is  impossible 
for  a  wheel  to  move  as  fast  as  the  stream  which  turns  it,  yet, 
if  their  velocities  bear  the  same  ratio  to  the  time  of  the  fall 
through  their  diameters,  the  wheel  16  feet  in  diameter 
may  move  twice  as  fast  as  the  wheel  4  feet  diameter.” 


TABLE. 


Height 
of  the  fall  in 
feet. 

Time  of 
falling  in 
seconds. 

Height 
of  the  fall  in 
feet. 

Time  of 
falling  in 
seconds. 

1 

.25 

14 

.935 

2 

.352 

16 

1. 

3 

.432 

20 

1.117 

4 

.5 

24 

1.22 

5 

.557 

25 

1.25 

6 

.612 

30 

1.37 

7 

.666 

36 

1.5 

8 

.706 

40 

1.58 

9 

.75 

45 

1.67 

10 

.79 

50 

1.76 

12 

.864 

Power  and  effect. — The  power  water  has  to  produce 
mechanical  effect,  is  as  the  quantity  and  fall  of  perpendi¬ 
cular  height. — The  mechanical  effect  of  a  wheel  is  as  the 
quantity  of  water  in  the  buckets  and  the  velocity. 

The  power  is  to  the  effect  as  3  :  2,  that  is,  -suppose  the 

power  to  be  9000,  the  effect  will  be  =  — X  2  = 

3  3 

=  6000. 

Height  of  the  wheel. — The  higher  the  wheel  is  in 
proportion  to  the  fall,  the  greater  will  be  the  effect,  because 
it  depends  less  upon  the  impulse,  and  more  upon  the  gra - 
'  vity  of  the  water  ;  however,  the  head  should  be  such,  that 
the  water  will  have  a  greater  velocity  than  the  circumfer¬ 
ence  of  the  wheel  :  and  the  velocity  that  the  circumference 


306 


WATER  WHEEL. 


ot  the  wheel  ought  to  have,  being  known,  the  head  required 
to  give  the  water  its  proper  velocity,  can  easily  be  known 
from  the  rules  of  Hydrostatics. 

Velocity  of  the  wheel. — Banks,  in  the  foregoing 
quotation,  says,  “  That  the  circumferences  of  overshot 
wheels  of  different  sizes  may  move  with  velocities  as  the 
square  roots  of  their  diameters,  without  disadvantage.”  — 
Smeaton  says,  “  Experience  confirms  that  the  velocity 
of  3  feet  per  second  is  applicable  to  the  highest  overshot 
wheels,  as  well  as  the  lowest;  though  high  wheels  may 
deviate  further  from  this  rule,  before  they  will  lose  their 
power,  by  a  given  aliquot  part  of  the  whole,  than  low  ones 
can  be  admitted  to  do  ;  for  a  24  feet  wheel  may  move  at 
the  rate  of  6  feet  per  second,  without  losing  any  consider¬ 
able  part  of  its  power.” 

It  is  evident  that  the  velocities  of  wheels,  will  be  in  pro¬ 
portion  to  the  qnantity  of  water  and  the  resistance  to  be 
overcome  : — if  the  water  flows  slowly  upon  the  wheel, 
more  time  is  required  to  fill  the  buckets  than  if  the  water 
flowed  rapidly  ;  and  whether  Smeaton  or  Banks  is  taken 
as  a  data,  the  raill-wright  can  easily  calculate  the  size  of 
his  wheel,  when  the  velocity  and  quantity  of  water  in  a 
given  time  is  known. 


example  i. 

What  power  is  a  stream  of  water  equal  to,  of  the  follow¬ 
ing  dimensions,  viz.  12  inches  deep,  22  inches  broad; 
velocity  7(J  feet  in  Ilf-  seconds,  and  fall  60  feet? — Also, 
what  size  of  a  wheel  could  be  applied  to  this  fall  ? 

12  X  22 

- —  =  1.S3  square  feet : — area  of  stream. 

144  1 

1  If-" :  70 :  :  60"  :  357.5  lineal  feet  per  min. — velocity. 
357.5  X  1.83  =  654.225  cubic  feet  per  minute. 

654.225  X  62.5  =  40889.0625  avoir,  libs  per  minute. 
40889.0625  X  60  =  2453343.7500  momentum  at  a  fall  of 

60  feet 


2453343.7500 

44000 


65.7  horse  power. 


3:2::  55.7  :  37.13  effective  power. 


WATER  WHEEL. 


397 


The  diameter  of  a  wheel  applicable  to  this  fall,  will  be 
58  feet,  allowing  one  foot  below  for  the  water  to  escape, 
and  one  foot  above  for  its  free  admission. 

58  X  3.1416  =  182.2128  circumference  of  wheel. 

60  X  6  =  360  feet  per  minute,  =  velocity  of  wheel. 

654.225  .  .  , 

- =  1.8  sectional  area  of  buckets. 

360 

The  buckets  must  only  be  half  full,  therefore  1.8x2  = 
3.6  will  be  the  area. 

To  give  sufficient  room  for  the  water  to  fill  the  buckets, 
5  3.6 

the  wheel  requires  to  be  four  feet  broad,  now  —  =  .9,  say 

1  foot  depth  of  shrouding. 

360  . 

- - =  1.9  revolutions 

182.2128 

make. 

Power  of  water 
Effective  power  of  do. 

Dimensions  (  Diameter 
of  <  Breadth 


per  minute  the  wheel  will 


=  55.7  h.  p. 
=  37.13  h.  p. 
=  58  feet. 
=  4  feet. 


wheel.  (  Depth  of  shrouding  =  1  foot. 


EXAMPLE  II. 


What  is  the  power  of  a  water  wheel,  16  feet  diameter, 
12  feet  wide,  and  shrouding  15  inches  deep  ? 

16  X  3.1416  =  50.2656  circumference  of  wheel. 

12  X  1  \  =  15  square  feet,  sectional  area  of  buckets. 

60  X  4  =  240  lineal  feet  per  minute,  =  velocity. 

240  x  15  =  3600  cubic  feet  water,  when  buckets  are  full 
when  half  full,  1800  cubic  feet. 

1800  X  62.5  =112500  avoir,  libs  of  water  per  minute. 
112500  X  16  =  1800000  momentum  falling  16  feet. 


3:2  : 


1200000 

:  1800000  :  =  27  horse  power. 

44000 


Buckets. — The  number  of  buckets  to  a  wheel  should  be 
as  few  as  possible,  to  retain  the  greatest  quantity  of  water ; 
and  their  mouths  only  such  a  width  as  to  admit  the  requisite 
34 


398 


WATER  WHEEL. 


quantity  of  water,  and  at  the  same  time  sufficient  room  to 
allow  the  air  to  escape. 

The  communication  of  power. — There  are  no  prime 
movers  of  machinery  from  which  power  is  taken  in  a  greater 
variety  of  forms  than  the  water  wheel,  and  among  such  a 
number  there  cannot  fail  to  be  many  bad  applications. 

Suffice  it  here  to  mention  one  of  the  worst,  and  mostge 
nerally  adopted.  For  driving  a  cotton  mill  in  this  neigh, 
bourhood,  there  is  a  water  wheel  about  12  feet  broad,  and 
20  feet  diameter  ;  there  is  a  division  in  the  middle  of  the 
buckets  upon  which  the  segments  are  bolted  round  the 
wheel,  and  the  power  is  taken  from  the  vertex  :  from  this 
erroneous  application,  a  great  part  of  the  power  is  lost ;  for 
the  weight  of  water  upon  the  wheel  presses  against  the  axle 
in  proportion  to  the  resistance  it  has  to  overcome,  and  if  the 
axle  was  not  a  large  mass  of  wood,  with  very  strong  iron 
journals,  it  could  not  stand  the  great  strain  which  is  upon  it. 

The  most  advantageous  part  of  the  wheel,  from  which 
the  power  can  be  taken,  is  that  point  in  the  circle  of  gyra- 
tion  horizontal  to  the  centre  of  the  axle  ;  because,  taking 
the  power  from  this  part,  the  whole  weight  of  water  in  the 
buckets  acts  upon  the  teeth  of  the  wheels ;  and  the  axle 
of  the  water  wheel  suffers  no  strain. 

The  proper  connexion  of  machinery  to  water  wheels  is 
of  the  first  importance,  and  mismanagement  in  this  parti¬ 
cular  point  is  often  the  cause  of  the  journals  and  axles 
giving  way,  besides  a  considerable  loss  of  power. 

To  find  the  radius  of  the  circle  of  gyration  in  a  water 
wheel  is  therefore  of  advantage  to  the  saving  of  power, 
and  the  following  example  will  show  the  rule  by  which  it 
is  found. — See  Centre  of  Gyration. 


EXAMPLE. 

Required  the  radius  of  the  circle  of  gyration  in  a  water 
wheel,  30  feet  diameter  ;  the  weight  of  the  arms  being  12 
tons,  shrouding  20  tons,  and  water  15  tons. 


PUMPS. 


399 


30  feet  diameter,  radius  —  15  feet. 

S  2U  x  152  =  4500  X  2  =  9000  ^  The  opposite  side  of 
A  12  X  152  i  the  water  wheel 

- -  a=  900  X  2  =  1800  J  must  be  taken. 


W  15  X  152  =  3375  =  3375 


2  X  20  +  12  =  64 
W  15 

79 

of  which  is  13  -fc  feet,  the 


14175 

- =  179,  the  square  root. 

79 

radius  of  the  circle  of  gyration. 


PUMPS. 

There  are  two  kinds  of  pumps,  lifting  and  forcing.  The 
lifting,  or  common  pumps,  are  applied  to  wells,  &c.,  where 
the  depth  does  not  exceed  32  feet ;  for  beyond  this  depth 
they  cannot  act,  because  the  height  that  water  is  forced  up 
into  a  vacuum,  by  the  pressure  of  the  atmosphere,  is  about 
34  feet. 

The  force  pumps  are  those  that  are  used  on  all  other  oc¬ 
casions,  and  can  raise  water  to  any  required  height. 
Bramah’s  celebrated  pump  is  one  of  this  description,  and 
shows  the  amazing  power  that  can  be  produced  by  such 
application,  and  which  arises  from  the  fluid  and  non-com- 
pressible  qualities  of  water. 

The  power  required  to  raise  water  any  height  is  equal 
to  the  quantity  of  water  discharged  in  a  given  time,  and 
the  perpendicular  height. 


EXAMPLE. 


Required  the  power  necessary  to  discharge  175  ale  gal« 

Ions  of  water  per  minute,  from  a  pipe  252  feet  high  1 

One  ale  gallon  of  water  weighs  10-J-  libs  avoir,  nearly. 

175  X  10i  =  1799  X  252  =  453348 

4  -=10.3  horse  power 


44000 


400 


pump*. 


The  following  is  a  very  simple  Rule,  and  easily  kept  in 
remembrance. 

Square  the  diameter  of  the  pipe  in  inches,  and  the  pro 
duct  will  be  the  number  of  libs  of  water  avoirdupois  con« 
tained  in  every  yard  length  of  the  pipe.  If  the  last  figure 
of  the  product  be  cut  off,  or  considered  a  decimal,  the  re¬ 
maining  figures  will  give  the  number  of  ale  gallons  in  each 
yard  of  pipe  ;  and  if  the  product  contains  only  one  figure, 
it  will  be  tenths  of  an  ale  gallon.  The  number  of  ale 
gallons  multiplied  by  282,  gives  the  cubic  inches  in  each 
yard  of  pipe,  and  the  contents  of  a  pipe  may  be  found  by 
Proportion. 

EXAMPLE. 

What  quantity  of  water  will  be  discharged  from  a  pipe 
5  inches  diameter,  252  feet  perpendicular  height,  the  water 
flowing  at  the  rate  of  210  feet  per  minute? 

210 

52  X  -7-  =  175  ale  gallons  per  minute. 

O 

252 

52  x  — —  =  2100  libs  water  in  pipe. 

2100  x  210 

— —  =  10  horse  power  required  to  pump  that  quan¬ 
tity  of  water. 

The  following  Table  gives  the  contents  of  a  pipe  one 
inch  diameter,  in  weight  and  measure,  which  serves  as  a 
standard  for  pipes  of  other  diameters,  their  contents  being 
fouud  by  the  following  rule. 

Multiply  the  numbers  in  the  following  Table  against 
any  height,  by  the  square  of  the  diameter  of  the  pipe,  and 
the  product  will  be  the  number  of  cubic  inches  avoirdu¬ 
pois  ounces,  and  wine  gallons  of  water,  that  the  given  pipe 
will  contain. 


EXAMPLE. 

How  many  wine  gallons  of  water  is  contained  in  a 
pipe  6  inches  diameter,  and  60  feet  long  ? 

2.4480  X  36  =  88.1280  wine  gallons. 

In  a  wine  gallon  there  are  231  cubic  inches. 


PUMPS, 


401 


TABLE. 


ONE  INCH  DIAMETER. 

Feet 

high. 

Quantity  in 
cubic  inches. 

Weight  in 
avoir,  oz. 

Gallons 
wine  measure. 

1 

9.42 

5.46 

.0407 

2 

18.85 

10.92 

.0816 

3 

28.27 

16.38 

.1224 

4 

37.70 

21.85 

.1632 

5 

47.12 

27.31 

.2040 

6 

56.55 

32.77 

.2448 

7 

65.97 

38.23 

.2423 

8 

75.40 

43.69 

.3264 

9 

84.82 

49.16 

.3671 

10 

94.25 

54.62 

.4OS0 

20 

188.49 

109.24 

.8160 

30 

282.74 

163.86 

1.2240 

40 

376.99 

218.47 

1.6300 

50 

471.24 

273.09 

2.0400 

60 

565.49 

327.71 

2.4480 

70 

659.73 

382.33 

2.8560 

80 

753.98 

436.95 

3.2640 

90 

848.23 

491.57 

3.6700 

100 

942.48 

546.19 

4.0800 

200 

1884.96 

1092.38 

8.1600 

The  resistance  arising  from  the  friction  of  water  flowing 
through  pipes,  &c.  is  directly  as  the  velocity  of  the  water, 
and  inversely  as  the  circumference  of  the  pipe. 

„  The  data  given  is  a  medium,  and  which  is  1  -5th  of  the 
whole  resistance  ;  this  is  the  standard  generally  adopted, 
being  considered  as  most  correct. 

EXAMPLE  I. 

What  is  the  power  requisite  to  overcomo  the  resistance 
and  friction  of  a  column  of  water  4  inches  diameter,  100 
feet  high,  and  flowing  at  the  velocity  of  300  feet  per  mi- 
nute  ? 

2  A 


34* 


402 


PUMPS. 


546.19  X  4 2 
16 


=  546.19,  say  546.2. 


546.2  X  300  . . 

- =  3.7  fth  of  which  is  .7,  therefore  the 

440UU 


power  required  to  overcome  the  resistance  occasioned  by 
the  weight  and  friction  of  the  water  will  be  3.7  -f-  .7  =  4.4 
H.  P.,  say  4.5  horse  power. 


EXAMPLE  II. 


There  is  a  cistern  20  feet  square,  and  10  feet  deep, 
placed  on  the  top  of  a  tower  60  feet  high  ;  what  power  is 
requisite  to  fill  this  cistern  in  30  minutes,  and  what  will 
be  the  diameter  of  the  pump,  when  the  length  of  stroke  is 
2  feet,  and  making  40  per  minute  ? 

20  x  20  x  10  =  4000  cubic  contents  of  cistern. 

4000 

— — -  =  133.3  cubic  feet  of  water  per  nunate. 
oO 

133.3X  1000 

- ; - =  8331.25  libs  avoir,  per  minute. 

16 

8331.25  X  60  ,  .  ,  . 

- — — - — =  11.36  horse  power,  l-5th  of  which  is 

44000  r 


2.27  -f-  11.11  =  13.63  horse  power  required. 

133.3 

, - =  1.7  X  144  =  244.80 

2  X  40=80  -  =  311.7,  now 

•  /o04 


y/  31 1.7  =  17.6  inches  diameter  of  pump  required. 

Founders  generally  prove  the  pipes  they  cast  to  stand  a 
certain  pressure,  which  is  calculated  by  the  weight  of  a.  per¬ 
pendicular  column  of  water,  the  area  being  equal  to  the 
area  of  the  pipe,  and  the  height  equal  to  any  given  height. 

To  ascertain  the  exact  pressure  of  water  to  which  a  pipe 
is  subjected,  a  safety  valve  is  used,  generally  of  1  inch 
diameter,  and  loaded  with  a  weight  equal  to  the  pressure 
required  :  for  example,  a  pipe  requires  to  stand  a  pressure 
of  300  feet,  what  weight  will  be  required  to  load  the  safe¬ 
ty  valve  1  inch  diameter?  . 

Feet.  Inches.  Ounces. 


300  X  12  =  3600  X  .7854  =2827.4400  X  1000 

1728 


=  1636-} 


“  1C2  libs  4-}-  oz.  weight  required. 


16 


PUMPS. 


403 


\ 


Each  of  the  weights  for  the  safety  valves  of  these  Hy¬ 
drostatic  proving  machines  are  generally  made  equal  to  a 
pressure  of  a  column  of  water  50  feet  high,  the  area  being 
the  area  of  the  valve. 

50  feet  of  pressure  on  a  valve  1  inch  diam.  =  17.06  libs. 


50  do. 

do. 

do. 

1| 

do. 

=  26.65  do. 

50  do. 

do. 

do. 

H 

do. 

=  38.38  do. 

50  do. 

do. 

do. 

2 

do. 

=  68.24  do. 

In  pumping,  there -is  always  a  deficiency  owing  to  the 
escape  of  water  through  the  valves  ;  to  account  for  this 
loss,  there  is  an  allowance  of  3  inches  for  each  stroke  ot 
piston  rod  :  for  example,  a  3  feet  stroke  may  be  calcula¬ 
ted  at  2  feet  9  inches. 

There  is  a  town,  the  inhabitants  of  which  amount  to 
12000,  arid  it  is  proposed  to  supply  it  with  water,  from  a 
river  running  through  the  low  grounds  250  perpendicular 
feet  below  the  best  situation  from  the  reservoir. 

It  is  required  to  know  the  power  of  an  engine  capable 
of  lifting  a  sufficient  quantity  of  water,  the  daily  supply 
being  calculated  at  10  ale  gallons  to  each  individual ; 
also,  what  size  of  pump  and  pipes  are  requisite  for  such  ? 

12000  X  10=  120000  gallons  per  day. 

120000 

Engine  is  to  work  12  hours,  — — —  =  10000  gallons  per 

1  z 

hour. 


10000 
60 


166.6  gallons  per  minute. 


The  pump  to  have  an  effective  stroke  of  3-f-  feet,  and 
making  30  strokes  per  minute. 

166-6 

— —  =  5.5583  gallons  each  stroke. 

30  s 

282  X  5.6  =  1579.2  cubic  inches  of  water  each  stroke. 
1579.2 

— -L-—  35.i  inches,  area  of  pump. 

3  feet  9  m.  =  45  m. 

351  _ 

• — —  =  44.7,  therefore  V  44.7  =  6.7  diam.  of  pump, 
7854  ’ 


404 


PUMPS. 


The  pipes  will  require  to  be  at  least  the  diameter  of  the 
pump  ;  if  they  are  a  little  more,  the  water  will  not  require 
to  flow  so  quickly  through  them,  and  thereby  cause  less 
'’fiction. 

The  power  of  the  engine  will  be 

16C.6gal.  X  10-J-lb.  X  250  feet  =  42G925  momentum 
426925 

— — — —  =  9.7,  add  1  -5th  =  11.64  horse  power. 

44000 

426925 


32000  13-3 


=  15.96  do.  Watt, 


426925 


=  18.6  do.  Desaguliers 


27500  “  15'5 


426925 


=  22.32  do.  Smeaton, 


MILL  WORK 


405 


This  table  is  inserted  from  Ferguson’s  Mechanical  Lectures. 
The  speed  is  calculated  for  a  millstone  six  feet  diameter;  but  as  mill¬ 
stones  in  general  use  are  seldom  more  than  four  feet  six  inches 
diameter,  the  speed  must  be  increased  accordingly  ;  and  it  is  found  by 
experience,  that  millstones  of  this  size  will  work  well  when  making 
120  revolutions  per  minute.  Such  a  mill  as  this,  with  a  water  wheel 
18  feet  diameter,  and  a  fall  of  water  about  feet,  will  require  about 
32  hogsheads  every  minute  to  turn  the  wheel  with  the  third  part  of 
the  velocity  with  which  the  water  falls,  and  to  overcome  the  resistance 
arising  from  the  friction  of  gears  and  attrition  of  the  stones  in  grinding 
the  corn. 


Height 
of  the 
fall  of 
water. 

Velocity 
of  the 
water  per 
second. 

Velocity 
of  the 
wheel  per 
second. 

Revolu¬ 
tions  of 
the  wheel 
per 

minute. 

Revolu¬ 
tions  of 
the  mill¬ 
stone  for 
one  of the 
wheels. 

Cogs  in  the 
wheel  and 
staves  in  the 
trundle. 

Revolu¬ 
tions  of 
the  mill¬ 
stone  per 
minute. 

Feet. 

Feet  and 
hundredth 
parts  of  a 
foot. 

Feet  and 
hundredth 
p°rts  of  a 
foot. 

Revolu¬ 
tions  and 
hundredth 
parts  of  a 
revolu¬ 
tion. 

Revolu¬ 
tions  and 
hundredth 
parts  of  a 
revolu¬ 
tion. 

Cogs. 

Staves. 

[Revolu¬ 
tions  and 
hundredth 
parts  of  a 
revolu¬ 
tion. 

1 

8.02 

2.67 

2.83 

21.20 

127 

6 

59.92 

2 

11.34 

3.78 

4.00 

15.00 

105 

7 

60.00 

3 

13.89 

-4.63 

4.91 

12.22 

98 

8 

60.14 

4 

16.04 

5.35 

5.67 

10.58 

95 

9 

59.87 

5 

17.93 

5.98 

6.34 

9.46 

85 

9 

59.84 

6 

19.64 

6.55 

6.94 

8.64 

78 

9 

60.10 

7 

21.21 

7.07 

7.50 

8.00 

72 

9 

60.00 

8 

22.68 

7.56 

8.02 

7.48 

71 

9 

59.67 

9 

24.05 

8.02 

8.51 

7.05 

70 

10 

59.57 

10 

25.35 

8.45 

8.97 

6.69 

67 

10 

60.09 

11 

26.59 

8.86 

9.40 

6.38 

64 

10 

60.16 

12 

28.77 

9.26 

9.82 

6.11 

61 

10 

59.90 

13 

28.91 

9.64 

10.22 

5.87 

59 

10 

60.18 

14 

30.00 

10.00 

10.60 

5.66 

56 

10 

59.36 

15 

31.05 

10.35 

10.99 

5.46 

55 

10 

60.48 

16 

32.07 

10.69 

11.34 

5.29 

53 

10 

60.10 

17 

33.06 

11.02 

11.70 

5.13 

51 

10 

59.67 

18 

34.02 

11.34 

12.02 

4.99 

50 

10 

60.10 

19 

34.95 

11.65 

12.37 

4.85 

48 

10 

60.61 

20 

35.86 

11.95 

12.68 

|  4.73 

47 

10 

59.59 

1 

2 

3 

4 

5 

6 

7 

t 


406  MILL  WORK. 


Table  showing  the  Relative  Poicer  of  Overshot  Wheels, 
Steam  Engines,  Horses,  Men ,  and  Windmills  of  diffe • 
rent  kinds,  brj  Fenwick. 


Number  of  ale  gallons  deli¬ 
vered  on  overshot  wheel 
10  feet  in  diameter,  every 
minute. 

Diameter  of  the  cylinder  in 
the  common  steam  engine, 
in  inches. 

Diameter  of  the  cylinder  in 
the  improved  steam'  en¬ 
gine,  in  inches. 

Number  of  horses,  working 
12  hours  per  day,  and 
moving  at  tiie  rate  of  two 
miles  per  hour. 

Number  of  men,  working  12 
hours  a  day. 

Radius  of  Dutch  sails  in 
their  common  position,  in 
feet. 

Radius  of  Dutch  sails  in 

their  best  position,  in  feet. 

Radius  of  Mr.  Smeaton’s  en¬ 

larged  sails,  in  feet. 

Height  to  which  these  diffe¬ 

rent  powers  will  raise  1000 
lbs.  avoirdupois  in  a  mi¬ 

nute. 

230 

8. 

6.12 

1 

5 

21.24 

17.89 

15.65 

13 

390 

9.5 

7.8 

2 

10 

30.04 

25.20 

22.13 

26  1 

528 

10.5 

8.2 

3 

15 

36.80 

30.98 

27.11 

39  * 

660 

11.5 

8.8 

4 

20 

42.48 

35.78 

31.30 

52 

720 

12.5 

9.3 

5 

25 

47.50 

40.00 

35.00 

65 

970 

14. 

10.55 

6 

30 

52.03 

43.82 

38.34 

78 

1170 

15.4 

11.75 

7 

35 

56.90 

47.33 

41.44 

90 

1350 

16.8 

12.8 

8 

40 

60.09 

50.60 

44  27 

104 

1455 

17.3 

13.6 

9 

45 

63-73 

53.66 

46.96 

117 

1584 

18.5 

14.2 

10 

50 

67.17 

56.57 

49.50 

130 

1740 

19.4 

14.8 

11 

55 

70.46 

59.33 

51.91 

143 

1900 

20.2 

15.2 

12 

60 

73.59 

61.97 

54.22 

156 

2100 

21. 

16.2 

13 

65 

76.59 

64.5 

56.43 

169 

2300 

22. 

17. 

14 

70 

79.49 

66.94 

58.57 

182 

2500 

23.1 

17.8 

15 

75 

82.27 

69.28 

60.62 

195 

2680 

23.9 

18.3 

16 

80 

84.97 

71.55 

62.61 

208 

2870 

24.7 

19. 

17 

85 

87.07 

73.32 

64.16 

221 

3055 

25.5 

19.6 

18 

90 

90.13 

75.90 

67.41 

234 

3240 

26.2 

20.1 

19 

95 

92.60 

77.9S 

68.23 

247 

3420 

27. 

20.7 

20 

100 

95.00 

80.00 

70.00 

260 

3750 

28.5 

22.2 

22 

110 

99.64 

83.90 

73.42 

286 

4000 

29.8 

23. 

24 

120 

104.06 

87.63 

76.68 

312 

4460 

31.1 

23.9 

26 

130 

108.32 

91.22 

79.81 

3S8 

4850 

32.4 

24.7 

28 

140 

112.20 

94.66 

82.82 

364 

5250 

33.6 

25.5 

30 

150  1 

116.35 

97.98 

85.73 

396 

STRENGTH  OF  MATERIALS. 


407 


ON  THE  STRENGTH  OP  MATERIALS. 


The  strength  of  materials  is  a  subject  of  great  import¬ 
ance  in  mechanics,  and  one  which,  of  all  the  branches  of 
this  useful  science,  is  the  least  understood.  Several  very 
eminent  mathematicians  have  exercised  their  talents  and 
ingenuity  in  forming  theories  for  estimating  the  strength  of 
beams  according  to  the  various  positions  in  which  they  are, 
but  unfortunately,  they  made  no  experiments  ;  therefore, 
they  had  no  better  foundation  than  mere  hypothesis  ;  con¬ 
sequently  are  totally  at  variance  with  practice. 

It  is  not  intended,  however,  in  this  short  abstract,  to 
perplex  the  reader  with  theory,  but  to  furnish  the  artisan 
with  a  few  properties,  which  to  him  will  be  more  useful 
than  many  discordant  suppositions. 

A  body  may  be  exposed  to  four  differentkinds  of  strains. 
1st.  It  may  be  torn  asunder  by  some  force  applied  in  the 
direction  of  its  length,  as  in  the  ca.se  of  ropes,  &c.  2d.  It 
may  also  be  crushed  by  a  force  applied  in  the  direction  of 
its  length,  as  in  the  case  of  pillars,  posts,  &c.  3d.  It  may 

be  broken  across  by  a  force  acting  perpendicularly  to  its 
length,  as  in  joints,  levers,  &c.  4th.  It  may  be  wrenched 
or  twisted  by  a  force  acting  in  a  kind  of  circular  direction 
at  the  extremity  of  a  lever,  as  in  the  case  of  wheel-axles, 
&c. 

The  first  of  these,  viz.  the  direct  cohesion  of  bodies,  is  one 
which  seldom  comes  under  the  consideration  of  the  mechan¬ 
ic  or  engineer  ;  and  if  any  former  experiments  can  be  ob¬ 
tained,  they  are  generally  sufficient  for  his  purpose  ;  or  no 
reason  can  be  assigned  why  the  strength  should  not  vary 
directly  as  ihe  section  of  fracture,  and  is  totally  indepen¬ 
dent  of  the  length  in  position,  except  so  far  as  the  weight 
of  the  body  may  increase  the  force  applied.  Neglecting 
this,  and  supposing  the  body  uniform  in  all  its  parts,  the 
strength  of  bodies  exposed  to  strains  in  the  direction  of 
their  length,  is  directly  proportionate  to  their  transverse 
area,  whatever  may  be  their  figure,  length,  or  position. 


408 


STRENGTH  OF  MATERIALS* 


Experiments  on  the  direct  cohesion  of  all  bodies  are  at¬ 
tended  with  great  difficulty,  in  consequence  of  the  enor¬ 
mous  force  required  to  produce  a  separation  of  the  parts,  in 
bars  of  any  considerable  dimensions. 

Some  experiments  of  this  kind,  however,  have  been 
made,  the  results  of  which  are  as  follow,  all  reduced  to  the 
section  of  a  square  inch. 


lbs. 

Gold  Cast, 

$  20,000 
(  24,000 

Silver  Cast, 

t  40,000 
{  43,000 

f  Japan, 

19,500 

Barbary, 

22,000 

Copper  Cast,  -< 

Hungary, 

31,000 

1 

Anglesea, 

34,000 

L  Sweden, 

37,000 

Iron  Cast, 

* 

$  42,000 
l  59,000 

r  Ordinary, 

65,000 

Iron  Bar,  < 

Stirian, 

BestSwedish&  Russian 

78,000 

84,000 

_  Horse  Nails, 

71,000 

Steel  Bar, 

Soft, 

»  Razor  tempered, 

120,000 

150,000 

"  Malacca, 

3,100 

Banca, 

3,600 

Tin  Cast,  •< 

Block, 

3,800 

' 

English  Block, 

5,200 

_  English  Grain, 

6,500 

Lead  Cast, 

860 

Regulus  of  Antimony, 

1,000 

Zinc, 

2,600 

Bismuth, 

2,900 

It  is  very  remarkable  that  almost  all  mixtures  of  metals 
are  stronger  or  more  tenacious  than  the  metals  themselves, 
much  depending  upon  the  proportion  of  the  ingredients ; 
and  these  proportions  are  different  in  metals. 

Oak,  9,000 

Ash,  17,000 

Pine,  from  10,000  to  13,000 


STRENGTH  OF  MATERIALS. 


409 


» 


On  the  Resistance  of  Bodies  when  pressed  longitudinally. 

It  is  obvious  that  a  body  when  pressed  endwise,  by  a 
sufficient  force,  may  be  crushed  and  destroyed,  either  by 
a  total  separation  of  the  matter  by  which  it  is  composed, 
or  by  bending  it,  whereby  it  is  broke  across  :  if  the  length 
of  the  body  be  very  inconsiderable  the  former  is  the  almost 
certain  result ;  but  if  its  length  be  much  more  than  its 
breadth  and  thickness,  it  generally  bends  before  breaking. 

Although  many  experiments,  and  some  very  intricate 
analytical  investigations  have  been  made  upon  this  subject, 
yet  little  can  be  advanced  that  will  be  of  use  to  the  practi¬ 
cal  engineer.  It  may  be  observed,  that  a  pillar  of  hard 
stone  of  Giory,  whose  section  is  a  square  foot,  will  bear 
with  perfect  safety  664,000  lbs.  ;  and  its  extreme  strength 
is  871,000  lbs. 

Good  brick  will  carry  with  safety  320,000  lbs.  on  a 
square  foot ;  and  chalk,  9,000  lbs. 

It  requires  a  power  of  400,000  lbs.  to  crush  a  cube  of 
one-quarter  of  an  inch  of  cast  iron. 

The  most  usual  strain,  and  therefore  the  one  with 
which  it  is  most  important  for  us  to  be  well  informed  is, 
that  by  which  a  body  is  broken  across,  from  the  force  of 
weight  acting  perpendicularly  or  obliquely  to  its  length, 
while  the  beam  itself  is  supported  by  its  two  extremities, 
or  by  one  end  fixed  into  a  wall,  or  otherwise. 

From  various  experiments  which  have  been  made,  the 
following  results  have  been  deduced  : 

1.  The  lateral  strength  of  beams  are  inversely  as  their 
lengths. 

2.  The  lateral  strengths  of  the  beams  are  directly  as 
their  breadth. 

3.  The  lateral  strength  of  beams  are  as  the  square  of 
their  depth. 

4.  In  square  beam3  the  lateral  strengths  are  as  the  cube 
of  one  side. 

5.  In  round  beams  as  the  cube  of  the  diameter. 

G.  The  lateral  strength  of  a  beam  with  its  narrow  face 
upwards,  is  to  its  strength  with  the  broad  face  upwards  as 


35 


410 


STRENGTH  OF  MATERIALS. 


the  breadth  of  the  broader  face  to  the  breadth  of  the  nar 
rower. 

7.  The  strength  of  beam  supported  only  at  its  extremes, 
is  to  the  strength  of  the  same  when  fixed  at  both  ends,  as 
1  to  2. 

S.  The  strength  of  a  beam  with  the  weight  or  load  sus¬ 
pended  from  the  centre  is  to  the  strength  when  the  load  is 
equally  divided  in  the  length  of  the  beam,  as  1  to  2. 

According  to  the  experiments  made  by  Mr.  Banks,  the 
worst  or  weakest  piece  of  oak  he  tried  bore  600  pounds, 
though  much  bended,  and  2  pounds  more  broke  it.  The 
strongest  piece  broke  with  974  pounds. 

The  worst  piece  of  Deal  bore  460  pounds,  but  broke 
with  4  more.  The  best  piece  bore  690  pounds,  but  broke 
with  a  little  more. 

The  weakest  cast  iron  bar  bore  2190  pounds,  and 
strongest  2980  pounds. 

Also,  these  experiments  were  made  upon  pieces  1  inch 
square,  the  props  exactly  1  foot  asunder,  and  the  weight 
suspended  from  the  centre,  the  ends  lying  loose. 

By  way  of  illustration  ire  will  add  a  feic  examples  for  the 
exercise  of  the  Reader. 

What  weight  suspended  from  the  middle  of  an  oak 
beam,  whose  length  is  10  feet,  and  each  side  of  its  square 
end  4  inches  ;  will  break  it  when  supported  at  each  end  ? 

By  article  1st,  the  lateral  strengths  of  beams  aro  in¬ 
versely  as  the  lengths,  and  (article  4)  as  the  cube  of  one 
side. 

Then,  as  a  piece  1  foot  long  and  1  inch  square  bore 
660  pounds,  one  10  feet  long  would  bear  66  lbs.,  and  66 
multiplied  by  64,  the  cube  of  4  =  4224  pounds  the  weight, 
the  above  beam  would  support.  If  the  ends  of  the  beam 
were  prevented  from  rising  it  would  bear  8448  pounds ; 
and  if  the  weight  was  equally  diffused  in  its  length,  it 
would  support  16S96  pounds. 

Required  the  strength  of  a  hollow  shaft  of  cast  iron  sup¬ 
ported  at  its  two  extremes,  5  inches  diameter,  the  diame¬ 
ter  of  the  hollow  being  4  inches,  and  the  length  of  th« 
shaft  10  feet  ? 


STRENGTH  OF  MATERIALS. 


411 


First  find  the  strength  of  a  solid  shaft  5  inches  diame¬ 
ter,  and  then  that  of  one  4  inches,  which  deduced  from  tha 
former,  gives  its  strength. 

The  strength  of  round  beams  are  as  the  cubes  of  their 
diameter,  and  the  cube  of  5  is  125  ;  this  multiplied  by  170, 
the  strength  of  a  round  bar  1  inch  diameter  and  10  feet 
long,  gives  21,375  pounds  for  the  strength  of  a  solid  shaft 
5  inches  diameter  and  10  feet  long. 

The  cube  of  4  is  64  multiplied  by  171,  equals  10,944 
pounds,  the  strength  of  a  solid  shaft  3  inches  diameterand 
10  feet  long.  Now  21,375—  10,944=  10,431  pounds, 
the  strength  of  the  hollow  shaft  required. 

N.  B.  The  diameter  of  a  solid  having  the  same  quantity 
of  matter  with  the  tube  is  3,  but  the  strength  of  it  would 
not  be  half  that  of  the  ring.  Engineers  have  of  late  in- 
troduced  this  improvement  into  their  machines,  the  axles 
of  cast  iron  being  made  hollow,  when  the  size  and  other 
circumstances  will  admit  of  it. 

Required  the  strength  of  a  piece  of  deal  6  inches  broad, 
2  inches  deep,  and  5  feet  long,  placed  edgeways,  and  the 
weight  suspended  from  the  centre  ? 

Jlnswer,  6624  pounds. 

What  weight  will  a  cast  iron  beam  bear  supported  in  th8 
centre,  the  length  of  the  beam  being  6  feet  8  inches  deep, 
and  1  inch  thick  ?  • 

Jlnswer,  10  tons,  8  cwt.  2  quarters,  and  8  lbs. 

If  a  plank  be  three  inches  thick,  and  12  inches  broad, 
now  much  more  will  it  bear  with  its  edge  than  with  its  flat 
side  uppermost  ? 

Jlnswer,  4  times  more  with  its  edge  uppermost. 

With  respect  to  the  fourth  strain  :  viz.  the  twist  to  which 
bars  or  shafts  in  an  upright  position  are  liable  by  the  wheel 
which  drives  them,  and  the  resistances  they  have  to  over¬ 
come,  little  that  will  be  satisfactory  can  be  advanced.  Mr. 
Banks  observes,  that  a  cast  iron  bar  an  inch  square,  and 
fixed  at  the  one  end,  and  631  pounds  suspended  by  a  wheel 
of  2  feet  diameter,  fixed  on  the  other  end,  will  break  by  the 


412 


STRENGTH  OP  MATERIALS. 


twist :  though  some  have  required  more  than  1000  pounds 
in  similar  situations  to  break  them  by  the  twist. 

The  strength  to  resist  the  twisting  strain  is  as  the  cube 

of  like  lateral  dimensions.  . 

In  concluding  these  plain  statements  it  may  be  necessa 
ry  to  remind  our  readers,  that  in  applying  these  rules  to 
practical  purposes,  care  should  be  taken  to  make  the  beams, 
&c.  sufficiently  strong  :  if  they  are  but  just  able  to  support 
the  stress  they  will  be  in  danger  of  breaking.  In  most 
cases  the  strength  should  be  2  or  3  times  the  stress,  and 
where  the  stress  may  be  in  equal,  or  the  pressure  exerted 
in  a  variable  manner,  by  jerks,  &c.  the  strength  should  be 

considerably  more  than  that. 

In  all  the  preceding  examples  the  beams  are  supposed 

only  just  able  to  support  the  load. 

The  following  are  the  results  of  experiments  made  by 
Mr.  Emerson,  which  state  the  load  that  may  be  safely 
borne  by  a  square  inch  rod  ot  each. 

Pounds  avoirdupoli 

*Iron  rod,  an  inch  square,  will  bear, 

Brass,  - 

Hempen  rope,  - 
Ivory,  - 

Oak,  box,  yew,  plumtree,  - 
Elm,  ash,  beech,  -  -  -  *  * 

Walnut,  plum,  - 

Bed  pine,  holly,  elder,  plane,  crab,  - 
Cherry,  hazel,  - 
Alder,  asp,  birch,  willow, 

Lead  - 
Free  stone,  - 

Mr.  Barlow’s  opinion  of  this  table  is,  “  Me  shall  ou-ry 
observe  here,  that  they  all  fall  very  short  of  the  ulti*  <ite 
strength  of  the  woods  to  which  they  refer.” 

Mr.  Emerson  z.lso  gives  the  following  practical  rule,  viz. 

*  Tenacity  of  copper  compared  with  iron  is  5  :  9  nearly,  or  1 :  t 
(.  t.  copper  being  1,  iron  is  1 A 


76,400 

35.600 

19.600 
15,700 

7,850 

6,070 

5,360 

5,000 

4,760 

4,290 

430 

914 


STRENGTH  OF  MATERIALS. 


413 


“that  a  cylinder,  whose  diameter  is  d  inches,  loaded  to 
one-fourth  of  its  absolute  strength,  will  carry  as  follows  : 

cwt. 

Iron,  ...  135  X  d2 

Good  rope,  -  -  22  x  d2 

Oak,  -  -  -  14  X  rf2 

Pine,  -  -  -  9  X  d2 

Captain  S.  Brown  made  an  experiment  on  Welsh  pig 
iron,  and  the  result  is  described  as  follows  : 

“A  bar  of  cast  iron,  Welsh  pig,  If  inch  square,  3  feet 
6  inches  long,  required  a  strain  of  1 1  tons  7  cwt.  (25,424 
libs,)  to  tear  it  asunder,  broke  exactly  transverse,  without 
being  reduced  in  any  part ;  quite  cold  when  broken,  par¬ 
ticles  fine,  dark  bluish  grey  colour.” — From  this  experi¬ 
ment,  it  appears  that  16,265  libs  will  tear  asunder  a  square 
inch  of  cast  iron. 

Mr.  G.  Rennie  also  made  some  experiments  on  cast 
iron,  and  the  result  was,  “  that  a  bar  one  inch  square,  cast 
horizontal,  will  support  a  weight  of  18,656  libs — and  one 
cast  vertical,  will  support  a  weight  of  19,488  libs.” 

There  have  been  several  experiments  made  on  mallea 
ble  iron,  of  various  qualities,  by  different  engineers. 

The  mean  of  Mr.  Telford’s  experiments,  is  29f  tons. 

The  mean  of  Capt.  S.  Brown’s  do.  is  25  do. 

and  the  mean  between  these  two  means,  is  27  tons,  near¬ 
ly  ;  which  may  be  assumed  as  the  medium  strength  of  & 
malleable  iron  bar  1  inch  square. 


From  a  mean,  derived  by  experiments,  performed  by 
Mr.  Barlow,  it  appears  that  the  strength  of  direct  cohesion, 
an  a  square  inch  of 

libs. 


Box  -  -  is  about 

Ash  -  — 

Teak  -  -  — 

Pine  -  -  — 


20,000 

17,000 

15,000 

12,000 


35* 


414 


STRENGTH  OF  MATERIALS. 


Beech  —  11,500 

Oak  —  10,000 

Pear  —  9,800 

Mahogany  .  —  -  8,000 

Each  of  these  weights  may  be  taken  as  a  correct  data 
for  the  cohesive  strength  of  the  wood  to  which  they  belong  , 
but  this  is  the  absolute  and  ultimate  strength  of  the  fibres  ; 
and  therefore,  if  the  quantity  that  may  be  safely  borne  be 
required,  not  more  than  two-thirds  of  the  above  values 
must  be  used. 

TABLE 

Of  Sizes  and  Strength  of  Chains. 


SPECIFIC  GRAVITY* 


415 


Ji  Table  of  Specific 


Platina  (pure) 

23000 

Fine  gold 

19400 

Standard  gold 

17724 

Quicksilver  (pure) 

14000 

Do.  (common) 

13600 

Lead 

11325 

Fine  silver 

11091 

Standard  silver 

10535 

Copper 

9000 

Copper  halfpence 

8915 

Gun  metal 

8784 

Cast  brass 

8000 

Steel 

7850 

Iron 

7645 

Cast  iron 

7425 

Coal 

1250 

Boxwood 

1030 

Sea  water 

1030 

Common  water 

1000 

Oak 

925 

Gunpowder  close 
shaken 

937 

Gunpowder  in  a 
loose  heap 

836 

Gravities  of  Bodies. 


Tin  '  7320 

Clear  crystal  glass  3150 

Granite  3000 

Marble  and  hard 

stone  .  2700 

Common  green 

glass  2600 

Flint  2570 

Common  stone  2520 

Clay  2160 

Brick  2000 

Common  earth  1984 

Nitre  1900 

Ivory  1825 

Brimstone  1810 

Solid  gunpowder  1745 

Sand  1520 

Ash  800 

Maple  755 

Elm  600 

Pine  550 

Charcoal  400 

Cork  .  240 

Air  at  a  mean  state  If 


Note.  The  several  sorts  of  wood  are  supposed  to  be 
dry.  Also,  as  a  cubic  foot  of  water  weighs  just  1000 
ounces  avoirdupois,  the  numbers  in  this  Table  express,  not 
only  the  specific  gravities  of  the  several  bodies,  but  also 
the  weight  of  a  cubic  foot  of  each  in  avoirdupois  ounces; 
and  therefore,  by  proportion,  the  weight  of  any  other  quan¬ 
tity,  or  the  quantity  of  any  other  weight,  may  be  known. 
Also,  100  cubic  inches  of  common  air  weigh  nearly  31f 
grains  troy,  or  If  drams  avoirdupois. 


416 


WEIGHT  OF  MALLEABLE 


TABLES  OP  THE  WEIGHT  OF  MALLEABLE  AND 
CAST  IRON  PLATES,  BARS,  &c. 


Table  of  the  Weight  of  a  Square  Foot  of  Cast  and 
Malleable  Iron,  Copper  and  Lead ,  from  1-16IA, 
to  2  inches  thick. 


Thick. 

Cast  iron. 

Mall 

iron. 

Copper. 

Lead. 

Libs 

oz. 

Libs.  oz. 

Libs. 

oz. 

Libs. 

oz. 

1  sixteenth 

2 

6.6 

2 

7.8  ' 

2 

15 

3 

11 

2  — 

4 

13.3 

4 

15.6 

5 

14 

7 

6 

3  — 

7 

4. 

7 

7.4 

8 

13 

11 

1 

4  — 

9 

10.6 

9 

15.2 

11 

12 

14 

12 

5  — 

12 

1.3 

12 

7.1 

14 

11 

18 

7 

6  — 

14 

8. 

14 

14.9 

17 

10 

22 

2 

7  — 

16 

14.7 

17 

6.7 

20 

9 

25 

13 

8  — 

19 

6.3 

19 

14.5 

23 

8 

29 

8 

9  — 

21 

12. 

22 

6.3 

26 

7 

33 

3 

10  — 

24 

2.7 

24 

14.2 

29 

6 

36 

14 

11  — 

26 

9.3 

27 

6. 

32 

5 

40 

9 

12  — 

29 

— 

29 

13.8 

35 

4 

44 

4 

13  — 

31 

6.7 

32 

5.6 

38 

3 

47 

15 

14  — 

33 

13.4 

34 

13.4 

41 

2 

51 

10 

15  — 

36 

4. 

37 

5.3 

44 

1 

55 

5 

1  inch 

38 

10.7 

39 

13.1 

47 

— 

59 

— 

H  — 

43 

8. 

44 

12.7 

52 

14 

66 

1 

1|  — 

48 

5.3 

49 

12.3 

58 

12 

73 

12 

If  — 

53 

2.7 

54 

12. 

64 

10 

81 

2 

If  — 

58 

— 

59 

11.6 

70 

8 

88 

8 

If  — 

62 

13.4 

64 

11.3 

76 

6 

95 

14 

If  — 

67 

10.7 

69 

10.9 

82 

4 

103 

4 

2  — 

77 

6.4 

79 

10.2 

94 

— 

118 

— 

AND  CAST  IRON  PLATES,  BARS,  ETC 


417 


Table  of  the  Weight  of  a  JJneal  Foot  of  Malleable  and  Cast  Iron  Bars ,  front 
6-16 ths  to  3  inches  square. 


Sixteenths 
on  the  side. 

Area  in 
square 
sixteenths. 

MALL.  IRON. 

Ounces  weight. 

CAST  IRON. 

Ounces  weight. 

ROUND  RODS. 

The  lfiths  on  the 
side  is  the  diametei 
of  rod. 

Ounces  weight. 

6 

36 

7.4736 

5.83 

7 

49 

10.1724 

7.99 

8 

64 

13.2864 

12.8960 

10.43 

9 

81 

16.8156 

• 

13.20 

10 

100 

20.7600 

•  • 

16.30 

11 

121 

25.1196 

•  •  • 

19.72 

12 

144 

29.8944 

29.0160 

23.47 

13 

169 

35.0844 

•  •  • 

27.53 

14 

196 

40.6896 

•  •  • 

31.94 

15 

225 

46.7100 

•  •  • 

36.44 

1  inch 

256 

53.1456 

51.5340 

41.50 

1 

2S9 

59.9964 

•  •  • 

46.80 

2 

324 

67.2624 

•  •  • 

52.47 

3 

361 

74.9436 

•  •  • 

58.46 

4 

400 

83.0400 

80.6000 

64.81 

5 

441 

91.5516 

•  •  • 

71.41 

6 

484 

100.4784 

•  *  * 

78.37 

7 

529 

109.8204 

•  •  • 

85.66 

8 

576 

119.5774 

116.0640 

93.27 

9 

625 

129.7500 

•  ■  • 

101.21 

10 

676 

140.3376 

•  •  • 

109.46 

11 

729 

151.3404 

•  •  • 

118.05 

12 

784 

162.7584 

157.9760 

126.95 

13 

841 

174.5916 

136.19 

14 

900 

186.8400 

•  •  • 

145.74 

15 

961 

199.5036 

•  •  • 

155.62 

2  inches 

1024 

212.5824 

206.3360 

165.82 

1 

1089 

226.0764 

•  •  • 

176.34 

2 

1156 

239.9856 

•  •  • 

187.19 

3 

1225 

254.3100 

•  •  • 

198.36 

4 

1296 

269.0496 

261.1440 

209.86 

5 

1369 

284.2044 

221.68 

6 

1444 

299.7744 

•  •  • 

233.83 

7 

1521 

315.7596 

.  .  .  • 

.  246.30 

8 

1600 

332.1600 

322.4000 

259.09 

9 

1681 

348.9756 

•  •  « 

272.20 

10 

1764 

366.2064 

285.64 

11 

1849 

3S3.8524 

•  •  • 

299.41 

12 

1936 

401  9136 

390.1040 

313.49 

13 

2025 

420.8900 

327.91 

14 

2116 

439.2816 

•  •  • 

342.64 

15 

2209 

458.5884 

•  • 

357.70 

3  inches 

3304 

4783104 

464.2560 

373.09 

2  B 


418 


SPECIFIC  GRAVITY. 


Example  to  show  the  application  of  the  foregoing  Tahli 
to  find  the  xc eight  of  Flat  Iron. 

What  is  the  weight  of  a  flat  bar  of  malleable  iron  3  in¬ 
ches  broad,  f  thick,  and  50  feet  long  1 

3  X  16  =  4S  X  3  =  144  square  16ths,  section  of  bar  : 
look  in  the  column  of  areas  in  the  Table,  and  opposite 
144  is  29.8944  oz.  weight  of  one  foot  of  the  bar,  multiply 
29.8944  by  50  feet  =  1494.72  oz.  or  93.42  lbs. 

Find  the  sixteenths  in  the  section  of  the  bar,  and  look 
for  the  number  in  the  column  of  areas  ;  if  the  number  be 
not  exact,  take  the  nearest  to  it. 

The  foregoing  Tables  have  been  calculated  from  Hut¬ 
ton’s  Specific  Gravities  ;  those  of  cast  and  malleable  iron 
and  lead  agree  very  nearly  with  those  given  by  other  au¬ 
thors  ;  but  the  specific  gravity  of  copper,  though  heavier 
than  that  given  by  Hatchett,  which  is  8.8U0  ;  still,  from 
copper  being  frequently  alloyed  with  lead,  it  is  supposed 
that  Hutton’s,  which  is  9000,  will  be  nearest  the  weight 
of  copper  commonly  used. 

As  a  Table  of  Specific  Gravities  is  often  found  useful, 

I  have  inserted  the  following  ;  but  for  calculating  the 

weights  of  metals,  I  would  recommend  Dr.  Hutton’s 

_  1 

Table.  See  page  49. 


TABLE 

OF 

SPECIFIC  GRAVITIES. 

METALS. 

Weight  of  a  cubic  i 
Specific  Gravity.  in  ounces  avoir. 

Arsenic, 

- 

. 

5763 

3.335 

Cast  antimony,. 

m 

- 

6702 

3.878 

Cast  zinc,  - 

- 

- 

7190 

4.161 

Cast  iron, 

- 

- 

7207 

4.165 

Cast  tin, 

- 

•  m 

7291 

4.219 

Bar  iron, 

m 

m  m 

7788 

4.507 

Cast  nickel, 

m 

«■  m 

7807 

4.513 

Cast  cobalt, 

- 

•  m 

7811 

4.520 

Hard  steel, 

m 

•  • 

7816 

4.523 

Soft  steel, 

• 

•  m 

7833 

4.533 

SPECIFIC  GRAVITY. 


419 


Cast  brass, 

* 

Specific  Gravity. 

Weight  of  a  cubic  inck 
in  ounces  avoir. 

-  8395 

4.858 

Cast  copper, 

. 

8788 

5.085 

Cast  bismuth, 

- 

*  9822 

5.6S4 

Cast  silver,  - 

• 

10474 

6.061 

Hammered  silver, 

• 

-  10510 

6.082 

Cast  lead, 

- 

11352 

6.569 

Mercury, 

Jeweller’s  gold, 

- 

-  1356S 

7.872 

• 

15709 

9.091 

Gold  coin, 

- 

-  17647 

10.212 

Cast  gold,  pure, 

m 

19258 

11.145 

Pure  gold,  hammered, 

- 

*  19361 

11.212 

Platinum,  pure, 

- 

19500 

11.285 

Platinum,  hammered, 

- 

-  20336 

11.777 

Platinum  wire, 

- 

-  21041 

12.176 

Note.  All  metals  become  specifically  heavier  by  ham¬ 
mering. 

STONES,  EARTHS,  &C. 

Specific  Gravity. 

Weight  of  a  cub.  fool 
in  lbs.  avoir. 

Brick, 

- 

2000 

125.00 

Sulphur, 

- 

-  2033 

127.08 

Stone,  paving, 

• 

2416 

151.00 

Stone,  common, 

m 

-  2520 

157.50 

Granite,  red, 

m 

-  2654 

165.84 

Glass,  green, 

• 

2642 

Glass,  white, 

m 

-  2892 

Glass,  bottle, 

. 

2733 

Pebble, 

• 

-  2664 

166.50 

Slate,  - 

* 

2672 

167.00 

Marble, 

m 

-  2742 

171.38 

Chalk, 

m 

2784 

174.00 

Basalt, 

m 

-  2864 

179.00 

Jrfone,  white  razor, 

- 

2876 

179.75 

Limestone, 

-  3179 

RESINS,  &C. 

198.68 

Wax, 

m 

897 

Tallow,  -  - 

m 

-  945 

Bone  of  an  ox, 

• 

.  1659 

Ivory,  - 

;  1 

•  1822 

420 


■PBCIFIC  GRAVITV, 


LIQUIDS. 

Weight  of  a  cnb.  foot 


Specific  Gravity. 

in  lba.  avoir. 

Air  at  the  earth’s  surface, 

• 

If 

Oil  of  turpentine, 

• 

870 

Olive  oil,  .  • 

• 

915 

Distilled  water, 

• 

1000 

Sea  water,  . 

• 

1028 

Nitric  acid, 

• 

1218 

Vitriol, 

• 

1841 

v 

WOODS. 

Cork, 

• 

246 

15.00 

'  9 

Poplar, 

• 

3S3 

23.94 

Larch,  •  •  • 

• 

544 

34.00 

Elm  and  new  English  pine, 

556 

34.75 

Mahogany,  Honduras, 

m 

560 

35.00 

Willow, 

• 

585 

36.56 

Cedar,  .  .  . 

• 

596 

37.25 

Pitch  pine,  . 

560 

41.25 

Pear  tree, 

• 

661 

41.31 

Walnut, 

• 

671 

41.94 

Pine,  forest, 

• 

694 

43.37 

Elder,  . 

• 

695 

43.44 

Beech, 

• 

696 

43.50 

Cherry  tree, 

• 

715 

44.68 

Teak, 

745 

46.56 

Maple  and  Riga  pine, 

750 

46.87 

Ash  and  Dantzic  oak, 

• 

760 

47.50 

Yew,  Dutch, 

• 

788 

49.25 

Apple  tree, 

• 

793 

49.56 

Alder,  .  . 

• 

800 

60.00 

Yew,  Spanish,  . 

• 

807 

50.44 

Mahogany,  Spanish, 

• 

852 

53.25 

Oak,  American, 

• 

872 

54.50 

Boxwood,  French, 

• 

912 

57.00 

Logwood, 

• 

913 

57.06 

Oak,  English, 

• 

970 

51.87 

Do.  sixty  years  cut, 

• 

1170 

73.12 

Ebony, 

• 

• 

1331 

83.18 

Lignum  vitse,  .  • 

• 

• 

1333 

83.31 

APPLICATION. 


421 


Application  of  the  foregoing  Table. 

A  block  of  marble,  measuring  6  feet  long  and  4  feet 
square,  lie3  at  a  wharf,  and  the  wharfinger  wishes  to  know 
if  his  10  ton  crane  is  sufficiently  strong  to  lift  it. 

6  X  4  X  4  =  96,  cubic  feet  in  the  block. 

171.38  lbs.  weight  of  a  cubic  foot.  ( See  Table.) 

171.38  X  96  _  rj  jon  y  cwt>  weight  of  block, 
lbs.  in  l  ton  =  2240 

The  10  ton  crane  is  therefore  sufficiently  strong  to  unit. 


* 


There  are  several  slabs  of  limestone  which  measure  al¬ 
together  300  cubic  feet,  and  it  is  proposed  to  bring  them 
down  a  river  on  a  raft  formed  of  teak  logs,  and  which  can 
most  conveniently  form  a  raft  42  feet  long  and  18  feet 
broad,  what  depth  shall  it  require  to  be  to  float  the  slabs  ? 


198.7  lbs.  weight  of  a  cubic  foot  of  limestone.  (See  Table.) 


-  —  62.5  lbs.  weight  of  a  cubic  feet  of  water. 

16 

198.7  X  300 


=  15  inches  depth  the  slabs  will  sink  the 

18  X  42  X  62.5  raft- 

1000  :  12  :  :  745  :  9,  that  is  a  cubic  foot  of  teak  sinks  9 
inches  in  water,  of  course  3  inches  of  wood  above  water ; 


therefore--  =  5  feet  depth  the  raft  will  sink  with  the  slabs, 

which,  added  to  9  inches,  gives  the  depth  the  raft  will  sink 
in  the  water,  and  therefore  the  raft  should  not  be  made  less 
than  6  feet  deep. 


12  :  6  :  :  9  : 4.5  =  depth  the  raft  will  sink. 

1.25  =  depth  the  slabs  will  sink  the  raft. 

6.75  =  depth  the  raft  will  sink  in  the  water 
when  carrying  the  slabs. 

36 


422 


PROPERTIES  OF  BODIES. 


-Table  of  the  Properties  of  Various  Bodies. 


BODIES. 


WOODS. 


Ash 

Beech 

Elm 

Yellow  and  Red  Pine 
White  d0. 

Mahogany 
English  Oak 
linerican  Yellow  Pine 
Larch 


METALS. 

Cast  Brass 
Cast  Iron 
Copper 

f Malleable  Iron 
Hammered  do. 
Cast  Lead 
■''tee  I 
ast  Tin 
Cast  Zinc 
Cast  Gun  Metal 


STONE,  &c. 

Brick 

Chalk 

Clay 

Aberdeen  Granite 
White  Marble 
Bed  Porphyry 
Welsh  Mate 
Portland  Stone 
Bath  do. 
Craigleith  do. 
Dundee  do. 


> 

rS 

o 

o 

<c 

•3 

o 

— 

02 


0.75 
0  01)6 
0.544 
0.557 
0.47 
0  5G 
0.83 
0.4G 
0.500 


8  37 
7.20i 
8.75 
7.6 


11.352 
7.84 
7.201 
7.028 
8.153  509.J3 


J.ibs. 

47.5 

45.3 

34. 
34.8 

29.3 

35. 
52. 
26.7 
35. 


450. 

519. 

475. 

487. 

709.5 

490. 

455.7 


1.841 

3.215 

0. 

2.025 

2.706 

2.871 

2.752 

2.113 

1.975 

2.362 

2.621 


115. 

144.7 

125. 

164. 

169. 

179. 

172. 

132. 

123.4 

147.0 

163.R 


1 

Will  bear  on  a  squnre 
inch  without  per¬ 

manent  alteration. 

Melts  at  degrees. 

Cohesive  force  of  a 

square  inch. 

Crushed  by  a  force 

on  square  inch. 

Absorbs  of  its 

weight  of  water. 

.  Libs. 

354 ( 

— 

23GC 

— 

3241 

— 

«  «.  _ 

_ 

4291 

— 

3631 

380t 

— 

3961 

5  390< 

— 

2065 

• 

6700 

I860 

18000 

15300 

3479 

-  -  - 

93001 

-  -  - 

17800 

2548 

33000 

1500 

612 

2880 

4421 

130000 

5700 

048 

10000 

•  -  - 

275 

562 

.066 

500 

10910 

-  "  - 

-  -  - 

1811 

6000 

*  '  - 

— 

-  -  - 

35508 

®  "  ” 

11500 

857 

3720 

.0625 

478 

-  -  - 

,0“7 

772 

5490 

.6158 

*  *  * 

-  .  - 

2661 

0030 

.002 

c. 

a 

c 

o 

5 

et 


73 


.23 

.15 

.21 

.3 

.23 

.24 


.25 

.130 


.435 


.090 

.182 

.365 

.65 


Br  the  last  column  of  this  Table,  the 
applied  to  the 


rules  for  the  strength  of  cast  Iron  can  b« 
various  bodies. 


with  Cast  Iron. 


TABLE  OF  WEIGHTS,  ETC 


423 


Table  of  the  Weight  of  Cast  Iron  Pipes. 


QJ 

O 

PQ 

ET"1 

|  Long. 

Weight. 

Bore. 

1  Thick. 

dl 

O 

J 

Weight. 

Bore. 

Thick. 

Long. 

Weight. 

i 

l 

4 

3  ft  6 

0 

0 

12 

64 

5 

8 

9 

3 

2 

21 

1  It1 

* 

* 

9 

7 

2 

8 

£ 

8 

3  ft  6 

0 

0 

21 

i 

9 

4 

1 

21 

1 

9 

10 

1 

2 

u 

4 

4  ft  6 

0 

0 

21 

1 

9 

6 

0 

14 

12 

1 

9 

5 

0 

24 

* 

4  ft  6 

0 

1 

4 

7 

1 

9 

2 

1 

7 

5 

a 

9 

6 

2 

8 

2 

1 

4 

6 

0 

1 

8 

1 

U 

9 

3 

0 

7 

3 

4 

9 

7 

3 

20 

£ 

8 

6 

0 

2 

0 

a 

9 

3 

3 

20 

1 

9 

10 

3 

0 

24 

1 

4 

6 

0 

1 

16 

3 

4 

9 

4 

3 

5 

121 

JL 

9 

5 

1 

16 

6 

0 

2 

10 

1 

9 

6 

2 

4 

5 

u 

9 

6 

3 

9 

2 

6 

0 

3 

10 

74 

£ 

a 

9 

2 

2 

4 

1 

4 

9 

8 

1 

0 

3 

1 

4 

9 

0 

2 

20 

1 

u 

9 

3 

1 

6 

1 

9 

11 

0 

21 

£ 

8 

9 

1 

0 

6 

5 

8 

9 

4 

0 

22 

13 

1 

9 

5 

2 

20 

1 

9 

1 

1 

12 

3 

■* 

9 

5 

0 

10 

5 

a 

9 

7 

0 

14 

5 

8 

9 

1 

3 

6 

1 

9 

7 

0 

0 

1 

9 

8 

2 

7 

3 

* 

9 

2 

J 

0 

8 

1 

Si 

9 

3 

2 

4 

l 

9 

11 

2 

12 

34 

J. 

4 

9 

0 

3 

0 

5 

s 

9 

4 

1 

25 

134 

1 

9 

5 

3 

7 

£ 

8 

9 

1 

0 

21 

1 

4 

9 

5 

1 

18 

5 

9 

7 

1 

12 

1 

2 

9 

1 

2 

14 

1 

9 

7 

1 

16 

3. 

9 

8 

3 

16 

5 

8 

9 

2 

0 

8 

84 

1 

9 

3 

3 

2 

1 

9 

11 

3 

24 

f 

9 

2 

2 

0 

5 

8 

9 

4 

2 

26 

14 

i 

9 

6 

0 

4 

4 

I 

9 

1 

1 

10 

3 

4 

9 

3 

2 

22 

"if 

9 

7 

2 

16 

i 

9 

1 

3 

12 

1 

9 

7 

3 

8 

3 

4 

9 

9 

1 

0 

5 

a 

9 

2 

j 

12 

9 

1 

9 

4 

0 

0 

I 

9 

12 

1 

14 

3 

4 

9 

2 

3 

21 

5 

8 

9 

3 

0 

4 

144 

1 

9 

6 

0 

24 

44 

£ 

8 

9 

1 

2 

2 

3 

4 

9 

6 

0 

2 

6 

I! 

9 

7 

3 

14 

1 

2 

9 

2 

0 

4 

1 

9 

8 

0 

26 

i 

9 

9 

2 

2 

6 

a 

9 

2 

2 

14 

94 

1 

9 

4 

0 

18 

1 

9 

12 

3 

6 

3 

4 

9 

3 

0 

21 

5 

8 

9 

5 

1 

0 

15 

ft 

9 

6 

1 

21 

5 

I 

9 

1 

2 

22 

i 

9 

6 

1 

6 

5 

8 

9 

8 

0 

14 

4 

9 

2 

1 

10 

1 

9 

8 

2 

20 

£ 

4 

9 

9 

3 

7 

! 

9 

2 

3 

17 

10 

1 

9 

4 

1 

10 

1 

9 

13 

0 

26 

3 

? 

9 

3 

1 

24 

5 

8 

9 

5 

1, 

26 

u 

9 

16 

3 

5 

51 

£ 

9 

1 

3 

10 

3 

4 

9 

6 

2 

14 

15i 

4 

9 

6 

2 

14 

i 

9 

2 

2 

0 

1 

9 

9 

0 

8 

3 

9 

8 

1 

14 

1 

9 

o 

O 

0 

IS 

104 

1 

9 

4 

2 

14 

f 

9 

10 

0 

10 

3 

* 

9 

3 

3 

7 

6 

9 

5 

3 

7 

1 

9 

13 

2 

17 

1 

9 

5 

0 

12 

1 

9 

7 

0 

0 

l* 

9 

17 

1 

6 

6 

? 

9 

2 

0 

0 

1 

9 

9 

2 

f 

16 

4 

9 

7 

0 

22 

i 

9 

2 

2 

21 

11 

i 

9 

4 

3 

14 

S 

8 

9 

8 

3 

7 

6 

8 

9 

3 

1 

17 

1 

9 

6 

0 

11 

1 

4 

9 

10 

1 

20 

1 

9 

4 

0 

It) 

3 

4 

9 

7 

1 

7 

1 

9 

14 

0 

8 

1 

9 

5 

2 

20 

1 

9 

9 

3 

20 

4 

9 

17 

3 

14 

6i 

1 

9 

2 

0 

16 

1 

2 

9 

5 

0 

7 

14 

9 

21 

3 

4 

h 

9 

2 

3|  20 

5 

u 

9 

6 

1 

12 

2 

9 

29 

3 

21 

424 


BORING  AND  TURNING. 


The  foregoing  Table  of  the  weight  of  cast  iron  pipes, 
gives  the  length  of  pipe  according  to  the  diameter  of  bore 
as  generally  used  in  practice. 

Diameter  of  bore  in  inches. 

Thickness  of  metal  in  inches. 

Length  of  pipe  in  feet. 

It  is  found  to  be  of  great  use  in  making  out  estimates 
of  pipes  : — for  instance,  it  is  required  to  know  the  weight 
of  a  range  of  pipes  225  feet  long,  7£  inches  diameter  of 
bore,  and  metal  f  of  an  inch  thick. 

9)225 

25  pipes  in  the  whole  length. 

One  pipe  weighs  4.0.  22,  which  multiplied  by  25,  is 
equal  to  104 . 3  .  18,  or  5  tons,  4  cwt.  3  quarters,  18  libs, 
weight  of  the  whole  range. 


The  following  is  a  Table  of  the  velocity  of  motion,  for 
boring  cast  iron  cylinders,  pumps,  &c.  and  heavy  turn¬ 
ing,  with  fixed  cutters. 

It  will  be  observed,  that  the  surface  bored  is  constantly 
the  same,  78.54  feet  per  minute  ;  this  velocity  is  found  to 
be  the  most  advantageous  :  a  velocity  greater  than  this, 
not  only  takes  the  temper  out  of  the  cutters,  but  also 
causing  more  heat,  expands  the  metal ;  and  if  the  ma¬ 
chine  stops  but  for  a  few  seconds,  a  mark  is  left  from  the 
contraction  of  the  metal. 

Turning  has  a  velocity  double  to  that  of  boring. 


BORING  AND  TURNING 


425 


TABLE. 


BORING. 

TURNING. 

Inches 

diameter. 

Revolutions  of 
bar  per  minute. 

Inches 

diameter. 

Revolution  of 
shaft  per  minute. 

1 

25. 

1 

50. 

2 

12.5 

2 

25. 

3 

8.33 

3 

16-67 

4 

6.25 

4 

12.50 

5 

5. 

5 

10. 

6 

4.16 

6 

8.32 

7 

3.57 

7 

7.15 

8 

3.125 

8 

6.25 

9 

2.77 

9 

5.55 

10 

2.5 

10 

5. 

15 

1.66 

15 

3.33 

20 

1.25 

20 

2.50 

25 

1. 

25 

2. 

30 

0.S33 

30 

1.667 

35 

0.714 

35 

1.430 

40 

0.625 

40 

1.250 

45 

0.56 

45 

1.12 

50 

0.5 

50 

1. 

60 

0.417 

60 

0.834 

70 

0.358 

70 

0.716 

80 

0.313 

SO 

0.626 

90 

0.278 

90 

0.556 

100 

0.25 

100 

0.50 

N.  B.  The  progression  of  the  cutters  may  be  1-1 6th  of 
an  inch  for  the  first  cut,  and  for  the  last  l-24th. 

If  hand  tools  are  employed  in  turning,  the  velocity 
.Aiay  be  considerably  increased. 


38* 


426 


BUILDING. 


BUILDING. 


LAVING  FLOORS. 

Flooring  boards  are  mostly  made  of  pine.  The  first  class 
are  selected  free  from  knots,  shakes,  sap-wood,  or  cross- 
grained  staff ;  the  second  class  consists  of  boards  also  free 
from  shakes  and  sap-wood,  but  not  from  small  sound  knots  ; 
the  third  class  contains  the  residue  of  any  parcel,  or  such 
boards  as  cannot  be  included  in  either  of  the  preceding 
classes.  When  an  agreement  is  entered  into  for  the  erec¬ 
tion  of  a  building,  the  quality  of  the  boards  should  be  spe- 
eified,  to  prevent  subsequent  disputes.  As  all  boards  shrink 
in  the  course  of  time,  and  as  the  quantity  of  their  contrac¬ 
tion  increases  with  their  dimensions,  floors  which  are  laid 
with  very  broad  boards,  soon  exhibit,  at  the  joints,  wide 
fissures  that  have  an  unpleasant  appearance.  It  is  therefore 
the  practice  in  good  houses,  not  only  to  select  the  best  part 
of  the  wood,  but  to  cut  the  boards  into  narrow  scantlings  ; 
so  that,  if  properly  seasoned,  and  laid  close  at  first,  their 
shrinking  afterwards  is  so  small  as  to  make  no  openings 
of  consequence.  Boards  about  five  inches  broad  may  be 
reckoned  narrow,  but  when  they  measure  nine  inches  or 
more  in  the  same  direction,  they  must  be  considered  broad. 

The  manner  of  jointing  floor  boards,  and  fastening 
them  down  upon  the  joists,  is  performed  in  a  variety  of 
ways,  the  most  usual  of  which'is,  to  plane  the  edges  of  the 
board  quite  square,  that  is,  at  right  angles  to  the  upper  and 
under  surface,  and  then,  placing  them  as  closely  to  each 
other  as  possible,  to  nail  them  down  from  the  upper  surface. 
Sometimes,  particularly  when  the  wood  is  known  to  be  in¬ 
sufficiently  seasoned  after  the  first  board  has  been  fastened 
down,  the  fourth  board  is  secured  in  like  manner,  the  two 
intermediate  boards  are  then  made  somewhat  wider  than  the 
space  to  receive  them,  and  forced  into  their  places  by  jump¬ 
ing  upou  them.  To  do  this  with  the  most  ease  andadvan. 
tage,  the  intermediate  boards  are  laid  aslant,  so  as  to  be 
highest  in  the  middle,  and  those  edges  which  are  placed 
together  being  sloped  a  little,  so  as  to  form  rather  less  than 
a  right  angle  with  their  respective  upper  serfaccs,  they  are, 


BUILDING. 


427 


by  an  adequate  weight,  at  once  compressed  and  levelled. 
The  fourth  board  of  the  last  series  becomes  the  first  of  the 
next,  and  the  operation,  which  is  called  folding  the  boards, 
is  repeated  till  the  floor  is  finished.  The  nails  are  driven 
in  a  little  below  the  surface  of  these  boards,  and  the  cavity 
is  filled  with  glazier’s  putty.  But  in  rooms  not  intended  to 
be  carpeted,  and  yet  where  a  neat  and  clean  appearance  is 
indispensable,  the  use  of  putty  must  be  avoided,  and  the 
nails  must  not  be  driven  in  from  the  top.  This  object  is 
obtained  by  doweling  the  joints,  that  is,  driving  wooden 
pins  into  them  in  the  middle  of  their  thickness,  and  par¬ 
allel  to  the  surface,  in  the  same  manner  as  the  coopers  joint 
the  boards  forming  the  ends  of  their  casks.  In  this  case, 
one-half  of  each  pin  entering  the  edges  placed  together, 
the  boards,  if  the  dowels  be  sufficiently  numerous  and  pro¬ 
perly  placed,  cannot  rise  or  sink  but  in  conjunction.  The 
best  place  for  the  dowels  is  in  the  middle  of  the  space  be¬ 
tween  the  joints.  In  the  best  doweled  work,  the  nails  are 
concealed  when  the  floor  is  finished,  for  they  are  driven 
in  slantwise  through  the  outer  edge  only  of  each  board. 
Sometimes. the  joints  of  flooring  boards  are  rabbeted,  that 
they  may  lap  over  each  other  a  little  way,  and  sometimes 
toothed  into  each  other,  or,  as  it  is  technically  expressed, 
ploughed  and  tongued.  When  either  of  these  methods  is 
adopted,  the  boards  are  not  separated  on  their  contraction 
so  as  to  leave  an  aperture  between  each  pair,  through  which 
any  thing  can  drop  ;  but  such  floors  are  more  costly  than 
others,  not  only  on  account  of  the  extra  labour,  but  the 
greater  quantity  of  wood  which  they  require. 

It  is  always  desirable  to  cover  a  floor  with  boards  in  one 
length  ;  but  as  this  may  not  always  be  convenient,  when 
it  is  not  done,  the  ends  of  the  two  boards  that  meet  are 
called  headings.  The  headings  should  invariably  be  upon 
a  joist,  and  two  of  them  should  never  be  together  in  the 
same  line. 

Before  the  boards  are  laid,  it  is  necessary  to  examine 
whether  the  upper  sides  of  the  joists  all  lie  in  the  same 
plane.  The  defect  they  are  most  liable  to,  is  that  of  being 
depressed  in  the  middle  ;  in  which  case  they  must  be 
raised  by  the  addition  of  suitable  pieces,  but  if  found  too 
protuberant,  they  must  be  reduced  by  the  adze. 


429 


BUIIJDING. 


Yellow  pine,  well  seasoned,  is  one  of  the  best  woods 
that  can  be  selected  for  floors,  and  retains  its  colour  for  a 
long  time  ;  whereas  the  white  sort,  by  frequent  washing, 
becomes  blackish  and  disagreeable  in  its  appearance. 


Proportion  of  Timbers,  $-c. 

In  the  treatise  entitled  the  “  British  Carpenter,”  already 
referred  to,  are  given  the  following  Tables  to  show  the  pro¬ 
portions  of  timbers  for  small  and  large  buildiugs  : 


PROPORTIONS  OF  TIMBERS  FOR  SMALL  BUILDINGS 


Bearing 
Height 
if  8  feet 

10 

12 

Posts  of  Pine 

Scantling 

4  inches  square 

5 

6 

Bearing 

Height 
if  10  feet 

12 

14 

Posts  of  Oalc 

Scantling 

6  inches  square 
8 

10 

Girdt 
Bearing 
if  16  feet 

20 

24 

>rs  of  Pine 

Scantling 

8  inches  by  11 
10  12$ 

12  14 

Gird 

Bearing 
if  16  feet 

20 

24 

ers  of  Oak 

Scantling 

10  inches  by  13 
12  14 

14  15 

Joist 
Bearing 
if  6  feet 

9 

12 

s  of  Pine 

Scantling 

5  inches  by  2$ 
6*  2J 

8  2J 

Joist 

Bearing 
if  6  feet 

9 

12 

s  of  Oak 

Scantling 

5  inches  by  3 
7J  3 

10  3 

Bridgx 
Bearing 
if  6  feet 

8 

10 

ngs  of  Pine 

Scantling 

4  inches  by  2$ 

5  S| 

6  3 

Bridgx 
Bearing 
if  6  feet 

8 

10 

ngs  oj'  Oak 

Scantling 

4  inches  by  3 
54  3 

7  3 

Small  R 
Bearing 
if  8  feet 

10 

12 

tflers  of  Pine 
Scantling 

3j  inches  by  2J 
4|  2 

5J  2i 

Small  R 
Bearing 
if  8  feet 

10 

12 

afters  of  Oak 
Scantling 

4a  inches  by  3 
54  3 

64  3 

Beams  oj 
Length 
if  30  feet 

45 

60 

Pine ,  or  Ties 
Scantling 

6  inches  by  7 

9  84 

12  11 

Beams  oj 
Length 
if  30  feet 

45 

60 

Oak,  or  Ties 
Scantling 

7  inches  by  8 

10  11| 

13  15 

BUILDING 


429 


Principal  Rafters  of  Pine 
Scantling 

Principal  Rafters  of  Oak 
Scantling 

Length 

Top 

Bottom 

Length 

Top 

Bottom 

if  24  feet 

5  by  7 

6  by  7 

if  24  feet 

7  by  8 

8  by  9 

36 

6J  8 

8  10 

36 

8  9 

9  104 

48 

8  10 

10  12 

48 

9  10 

10  12 

PROPORTION  OF  TIMBERS  FOR  LARGE  BUILDINGS. 


Bearing  Posts  of  Pine 

Height  j  Scantling 

if  8  feet  |  5  inches  square  ll 

12  |  8 

16  |  10 

Girdc 
Bearing 
if  16  feet 

20 

24 

rs  of  Pine 

Scantling 

9J  inches  by  13  i 
12  14 

134  15 

Joist 
Bearing 
if  6  feet 

9 

12 

s  of  Pine 

Scantling 

5  inches  by  3  i 
74  3 

10  3 

Bridgi 
Bearing 
if  6  feet 

8 

10 

ngs  of  Pine 

Scantling 

4  inches  by  3 

54  3 

7  3 

Small  R< 

Bearing 
if  8  feet 

10 

12 

flers  of  Pine 
Scantling 

44  inches  by  3 

54  -  3 

64  3 

Beams  oj 
Length 
if  30  feet 

45 

60 

r  Pine,  or  Ties 
Scantling 

7  inches  by  8 

10  114 

13  15 

•  Length 

Top 

if  24  feet 

7  by 

9 

36 

8 

9 

1  48 

9 

10 

Scantling 

Bottom 

8  by  9 

9  10i 

10  12 


Bearing  Posts  of  Oak 

Scantling 
8  inches  square 

12 
16 


Height 
8  feet 
12 
16 


Bearing 
16  feet 
20 
24 


Girders  of  Oak 

Scantling 
12  inches  by  14 
15  15 

IS  16 


Bearing 
6  feet 
9 

12 


Joists  of  Oak 

Scantling 
6  inches  by  3 
9  3 

12  3 


Bearing 
6  feet 
8 

10 


Br  idgings  of  Oak 


Scantling 
5  inches  by  34 
64  3) 

8  3J 


Bearing 


8  fee 

10 

12 


Small  Rafters  of  Oak 
Scantling 
54 inches  by  3 
7  3 

9  3 


Beams  of  Oak,  or  Ties 


Scantling 
8  inches  by  9 
11  124 
_  14  16 

Principal  Rafters  of  Oak 

Scantling 


Length 
'  30 
45 
60 


Length 
if  24  feet 
36 
48 


Top 

8  by  9 

9  10 

10  13 


Bottom 
9  by  12 
10  10 
12 


14, 


430 


BUILDING. 


The  author  of  the  preceding  Tables  observes,  that 
though  they  seem  so  plain  as  not  to  need  explanation,  yet 
a  few  remarks  might  be  subjoined  with  propriety.  All 
binding  or  strong  joists,  he  then  adds,  ought  to  be  half  as 
thick  again  as  common  joists  ;  that  is,  if  a  common  joist 
be  given  three  inches  thick,  a  binding  joist  should  be  four 
inches  and  a  half  thick,  although  of  the  same  depth. 

If  it  be  not  convenient  to  allow  the  posts  in  partitions 
to  be  square,  which  is  the  best  form,  in  such  cases,  multi¬ 
ply  the  square  of  the  side  of  the  posts,  as  here  given,  by  itself : 
for  instance,  if  it  be  six  inches  square,  then  as  six  times  six 
is  thirty-six,  to  keep  this  post  nearly  to  thte  same  strength, 
find  two  numbers  producing  the  same  amount;  as  suppose 
the  partition  to  be  four  inches  thick,  then  let  the  post  be 
nine  inches  the  other  way,  so  that  nine  times  four  being 
thirty-six,  the  area  of  its  horizontal  section  is  the  same, 
and  its  strength  nearly  equal  to  the  square  post. 

Posts  that  go  to  the  height  of  two  or  three  stories,  need 
not  hold  the  proportions  given  in  the  table,  because  at 
every  floor  they  meet  with  atie.  Admit  a  post  to  be  thirty 
feet  high,  and  that  in  this  height  there  are  three  stories, 
two  of  ten  feet  and  one  of  eight  feet ;  look  for  posts  of 
pine  ten  feet  high,  their,  scantling  is  five  inches  square, 
that  is,  twenty-five  square  inches,  which  double  for  the 
two  stories  ;  and  also  take  that  of  eight  feet  high,  being 
four  inches,  that  is,  sixteen  inches  square,  all  which  being 
added  together,  make  sixty-six  inches  ;  so  that  such  a 
post  would  be  rather  more  than  eight  inches  square.  On 
occasion  it  may  be  lessened  in  each  story  as  it  rises. 

All  beams,  ties,  and  principal  rafters,  ought  to  be  cut 
or  forced  in  framing  to  a  chamber,  or  roundness,  on  the 
upper  side,  and  the  convexity  may  be  about  one  inch  in 
eighteen  or  twenty  feet.  The  reason  is,  that  all  timber, 
partly  from  its  own  weight,  but  principally  from  the  weight 
of  the  covering  or  other  burden  it  has  to  bear,  will  swag  5 
and  unless  prepared  in  this  manner,  that  it  may  never  be. 
come  concave,  a  degree  of  unsightliness,  and  often  of 
inconvenience,  will  be  produced. 

The  joists  in  floors,  the  purlines  (or  timbers  into  which 
the  small  rafters  are  tenoned  in  roofs,)  &c.,  should  not  ex- 
•eed  twelve  feet  in  the  length  of  their  bearing,  or  from  sup« 


BUILDING. 


431 


port  to  support.  The  strong  joists  of  floors  should  not  be 
at  a  greater  distance  than  five  feet,  nor  common  joists 
more  than  ten  or  twelve  inches  apart. 

According  to  the  experiments  of  Muschenbroek,  pine  is 
able  to  bear  compression  in  the  direction  of  the  length  of 
its  fibres,  or  to  sustain  as  a  post,  a  much  greater  weight  than 
oak,  but  is  far  inferior  to  oak  when  the  weight  is  suspend¬ 
ed.  In  the  preceding  tables,  therefore,  the  scantlings  of 
pine  bearing  postsand  principal  rafters  are  properly  made 
less  than  those  of  oak  ;  but  for  other  timbers,  particularly 
for  ties,  many  are  of  opinion  that  the  proportions  of  the 
author’s  tables  should  be  reversed,  and  the  scantling 
which  he  has  assigned  to  pine  should  be  given  to  oak. 


432 


BRICKLAYERS*  WORK 


I 


OS 

O 

fe 

oo 

erf 

UJ 

<: 

w 

o 

5 

ca 


a 

•S 

t» 

a 


o  ~  J3 
z;  o  — 


2  £ 


jS  C3  H- 


O  3 


— 

a 

as 


3 

a 

3 

aS 


OT 

•— 

cn 

a> 

-3 


3 

o 

O 

to 


3  a 


-3 

3 

H 

HO 

s- 


HD 

(-4 

c3 

fcD  g 

£  3 

a  a 
a  ® 
a 
o 
a 


.2  ^  .a  w 
®-lS  — 


a 

E 

JS 

O 

a 

•73 

a 

3 

a 

as 

© 

a 

as 


3 

s 

*5 

3 

HO 

■b 

a 

3 

a 


3 
O 

a 

*■5 


a 

as 

3 

« 


,a 


“I 

-  -5 

”3  O 
•  — '  y 

a  w 
cc  as 


CO 

a 


as 

3 


.£ 

tin 


3 
3 

ST^ 

fT-, 

4-»  *TD 
W  fl  u 

«  o  o 
7  a 
Ha  a 


a  a 
a.  3 
^  .  o 


'a 

a 

<! 


t  (O  M 


to 

"3 

>_ 

3 


fcfl 

a 


,2  ^  3 


o 

to 

"3 

o 


^-2 

b- 


M  © 


a 

.a 


as 

a 

■s 


— «  a  o 


a  C 
■w  ^ 


r„  to 
©D-y 


to  .a 


5  ™  "  -5  CO 
S'-  -  °  — 
E 


a 

a: 

CO 


a 

a 

*-» 

a 

o 

a 

a 

as 


a 

a 

•*—* 

x 

a 

a 

o 

3 

a 

3 


a 

a 

*-» 

a 

o 

a 

a 

as 

-«-* 

*3 

a 

3 


a 

c2 

c*-. 

O 

a 

a 

as 

s 

3 

a 


a 

a 

JS 

o 

a 


TS 

a 

a 

a 

as 


-H  a. 

a  x  "H 
a 


a 


a 


"a  « 

g-.E  £  .5  - 

2  ”  "So 

K  —  .a  . 
— i  as  a  co 

M  3  g 

*15.2  a 


M 

a 

£ 

3 

O 

a 

o 


20 

id  .-t  ©  id  eo 
•*H<  os  ■'*  go  e$ 
CJ  t*  t-~  05  r-< 

15 

ID  ©  D>  ©  Q 
00  l''*  ID  ©  W 

i-t  to  id  © 

•  •  •  •  • 

12 

00  CD  TO  O  O 
rr  03  03  ^ 

i->  NH1  TO  b- 

3 

lOOCOtO 
mNO>#N 
r-t  CJ  rjc  TO  CO 
•  •  •  •  • 

10 

TOffiONO 
c/  tji  r>.  rf  i-t 

hnk^cc 

0) 

.111 

.222 

.333 

.444 

.555 

I 


CO 

ID 

(cnoow 

03  03  O  ID  03 

CHWCO'f 
.  •  •  •  • 

fcs 

.0363 

.173 

.260 

.345 

.432 

10 

.0743 

.148 

.222 

.296 

.370 

10 

.0615 

.123 

.184 

.246 

.307 

«• 

.0492 

.0933 

.148 

.196 

.246 

o 

TO  .-t  QD  ^ 
WNnrf  OD 
©  O  i— t  i— i  i— t 
•  •  •  •  • 

« 

.0246 

.0492 

.0738 

.0984 

.123 

H 

.0124 

.0247 

.0370 

.0492 

.0615 

No.  or 
bricks 
broatl. 

Second  Table  at  Ten  Feet  High. 


433 


bricklayers’  work. 


Feet. 

700 

CQ  CO  00  lO  rH 
^  b^  ©"  rH  CO 
00  rH  CQ  CO  TH 

Feet. 

600 

C  00  CQ  ©  © 

^  rH  CQ-  05  b.' 
i>  rH  CQ  CQ  CO 

Feet. 
500  i 

©  CO  rH  ©  b* 
'“2  CQ  00  rH  © 
CO  rH  rH  CQ  CO 

Feet. 

400 

o  in  oo  co 
°3  °°.  rj5  05  Hji 
rH  05  H  H  CQ 

Feet. 

300 

OOOOOU5 
«>  ^  ph'  rH  00 
Mt'HHH 

Feet. 

200 

CO  O  OO  rH  co 
rfiOSCOOD^ 

CQ 'd*  i>  ©  ' — 1 

Feet. 

100 

CO  CO  O  CQ  © 
CQ  b»  ©  rH 

-H  CQ  CO  ^  CD 

Feet. 

90 

rH  rH  CO  rH  CO 
rH  CQ  CO  rH  © 
rH  CQ’  CO  rH  ©’ 

Feet. 

80 

©  b»  ©  rH  cq 

00  05  05  05  05 

°R  ph  cq  co‘  rH 

Feet. 

70 

cq  co  oo  eo  rH 
©  b>  ©  rH  CO 
r-i  CQ  CO*  rH 

Feet. 

60 

©  00  CQ  O  O 
rH  rH  CQ  © 

^  rH  CQ  CQ  CO 

Feet. 

50 

©  co  rH  ©  b- 
rH  CQ  00  -^  © 

®.  rH  pH  CQ  CO* 

Feet. 

40 

©  CO  00  b*  © 

CO  00  rH  05  rH 

.  r"!  p—i  rH  CQ 

Feet. 

30 

OOHODt)! 

©  rH  rH  rH  00 

^  H  ri  pH 

No.  of 

bricks 

broad. 

pH  CQ  CO  rH  © 

1 

-e 


« 

j 

a 

■< 

H 

Q 

Pi 

I— < 

w 

H 


Q 


*3 

o 

Oh 

P 

m 

CO 

CD 

Sh 

o 

o 

T3 


H3 

P 

cti 

bo 

c 

r2 

03 

*-p 

f-t 

a 

>> 


03 

"O 

o 

o 


c 

0) 

> 

•  »“* 

bo 


a 

a> 

s 

o 

O 


C  TP 

a>  o 

*;  o 

O  c 


° 


w  03 
C  "C 
O)  o 

i« 

o  c 


a>  D 

£-§ 


«-»  03 

G  T3 

<13  O 

C  ° 
oOh 
O  £3 


Content 

in  Roods. 

CQ  00  rH  O  ©  rH  b. 
CQ  CQ  rH  ©  ©  © 

rH  rH  rH  rH  rH  i— 1  CQ 

Feet 

long. 

©  o  ©  ©  o  ©  © 

©  o  O  ©  ©  o  © 

00  ©  ©  rH  CQ  TO 

rH  pH  rH  pH 

Content 

in  Roods. 

rH  rH  00  00  fr  ©  © 
00  ©  rH  l>  CO*  ©  CD 
CQ  CO  CO  rH  ©  00  © 

Feet 

long. 

©©©©©©© 
00  ©  ©  ©  ©  ©  © 
pH  rH  CQ  CO  rH  IQ  © 

Content 
in  Roods. 

©  CQ  b^  CQ  00  rH  00 
05  ©'  cq’  CO  ©’  CD 
rH  rH  CQ  CQ  CQ  CQ  CQ 

Feet 

long. 

S3 

©©©©©©© 
rH  CQ  TO  rH  lO  ©  b> 

rH  rH  rH  rH  pH  rH  pH 

G  -d 

B  § 

O  c 


<u 


®  s 

fc-2 


CQ  QO  CD  rH  CQ 
h  CQ  CQ  CO  rH  Ifi  © 


©  ©  o  m  ©  m  o 
b-  ao  ao  ©  ©  © 


i>  b-  o  o  o  b*  rH 

io  m  n  o  oq  in  q 

O  CO  J>  00  00  ©  rH 


(OOiOOlOOiO 
CO  rH  ©  ©  ©  © 


^*#010  00  00 

cq  rH  co  cq  rH  ^  Qo 

rH  rH  rH  CQ  CO  rH 


ooffiomoino 

pH  rH  CQ  CQ  CO 


co  ao  ao  oo  o  o  cq 

lC  H  h>  M  O  O  H 

ph  cq  ■'*  cq  ao  05 


pH  CQ  CO  TH  ID  ©  fr* 


37 


2  C 


434 


CIRCLES  A.N  P  DIAMETER*. 


CIRCLES  AND  DIAMETERS. 


The  diameter  of  a  circle  being  given,  to  find  tne  cir¬ 
cumference  ;  or  the  circumference  being  given,  to  find 
the  diameter. 


RULE. 

Multiply  the  diameter  by  3. 1410,  and  the  product  will 
(be  the  circumference  ;  or, 

Divide  the  circumference  by  3.1416,  and  the  quoticn* 
will  be  the  diameter 

Note  1. — As  7  is  to  22,  so  is  the  diameter  to  the  cir- 
jumfercnce  ;  or,  as  22  is  to  7,  so  is  the  circumference  to 
.he  diameter. 


EXAMPLES. 

(1.)  If  the  diameter  of  a  circle  be  17,  what  is  the  cir¬ 
cumference  ? 

Here  3.1417  X  17  =  53.4072  =  circumference. 

(2.)  If  the  circumference  of  a  circlo  be  354,  what  i» 
the  diameter  ? 

354.000 

Here  -  -  =  112.681  —  diameter. 

o  1416 

(3.)  What  is  the  circumference  of  a  circle  whoso 
diameter  is  40  feet?  Ans.  125.6640. 

(4.)  What  is  the  circumference  of  a  circle  whoso 
diameter  is  12  feet?  Ans.  37.6992. 

(5.)  If  the  circumference  of  the  earth  be  25,000  miles, 
what  is  the  diameter?  Ans.  7958  nearly. 

(6.)  The  base  of  a  cone  is  a  circle  ;  what  is  its  diame¬ 
ter  when  the  circumference  is  54  feet  ?  Ans.  20.3718. 


DIAMETERS  AND  CIRCUMFERENCES 


435 


The  following  Table  contains  diameters  and  circumfe- 
rences  in  inches  and  parts,  from  half  an  inch  to  65  inches 


Diameter  in  Inches 
and  Half. 

i  — ■ 

Circumference  in 
Inches  and  Parts. 

1  Diameter  in  Indies 
and  Half. 

I  Circumference  in 

1  Inches  and  Parts. 

Diameter  in  Inches 
and  Half. 

l  Circumference  in 

[  Inches  and  Parts. 

Diameter  in  Inches 

and  Half. 

— - - 1 

Circumference  in 

Inches  and  Parts. 

Diameter  in  Inches 

and  Half. 

2 

1.57 

13* 

42.4 

26* 

83.25 

39* 

124.1 

52* 

1 

3.14 

14 

43.98 

27 

81.82 

40“ 

125.66 

53“ 

4.71 

141 

45.55 

27* 

86.39 

40* 

127.23 

53* 

2 

6.28 

15 

47.12 

28 

87.96 

41 

128.8 

54 

7.85 

15* 

48.70 

28* 

89.53 

41* 

130.37 

54*  1 

3 

9.42 

16 

50.26 

29 

91.1 

42 

131.94 

55  1 

10.99 

16* 

51.83 

29* 

92.67 

42* 

133.51 

55*  1 

4 

12-56 

17 

53.40 

30“ 

94.28 

43 

135. 

56  1 

4* 

14.13 

17* 

54.97 

30* 

95.81 

43* 

136.65 

56*  1 

5 

15.7 

18 

56.54 

31 

97.39 

44 

138.23 

57  1 

^  1 

17.28 

18* 

58.11 

31* 

98.96 

44* 

139.8 

57*  1 

0 

18.85 

19 

59.69 

32 

100.53 

45 

141.37 

58  1 

6* 

20.42 

191 

61.26 

32* 

102.1 

45* 

142.94 

58*  1 

7 

21.99 

20 

32.8 

33 

103.67 

46“ 

144.52 

59  1 

7X 

i2 

23.56 

201 

34.4 

33* 

105.24 

46* 

146 

59*  1 

8 

25.13 

21 

35.97 

34 

106.81 

47 

147.65 

60  1 

8i 

26.7 

R* 

37.54 

14* 

108.38 

47* 

149.22 

60*  1 

9 

28.27 

22“ 

39.11 

35 

109.95 

48“ 

150.79 

61“  1 

9* 

29.84 

22* 

70.7 

35* 

111.52 

48* 

152.36 

61*  1 

10 

31.4  v 

23 

7  2.25 

36 

113 

49 

153.93 

62  1 

10i 

32.98  5 

23* 

73.82 

36* 

11466 

19* 

155.5 

62*  I 

11 

34.55  • 

24 

75.4 

37 

116.23 

50 

157 

63  1 

Hi 

36.12  5 

lH 

76.9 

37* 

117.81 

50* 

[58.65 

63*  1 

12 

37.70  • 

25 

78.54 

38 

119.38 

51 

160.23 

64“  2 

39.27  • 

25A  * 

30.11 

38* 

120.9 

31* 

161.79 

34*  2 

13 

10.84  • 

26  |81.68 

39 

122.52, 

52 

163.36 

35  2 

CO 


EXAMPLE. 

Required  the  circumference  of  a  circle  of  7  inches 
diameter.  See  the  above  Table  ;  in  column  1st,  is  7  in¬ 
ches  diameter,  and  against  that,  in  column  2d,  is  21.99, 
or  what  might  be  considered  22. 


436 


STEAM  ENGINE 


THE  STEAM  ENGINE  RENDERED  EASY 

WITH  PLATES. 

Having  already  described  the  Steam  Engine  in  all  its 
operations,  the  design  here  is,  to  commence  with  it  in  its 
simplest  state,  and  to  proceed  to  a  full  description  of  the 
high  and  low  pressure  system  ;  for  the  more  immediate 
advantage  of  new  beginners,  and  those  who  have  not  had 
an  opportunity  of  studying  this  subject. 

Fig.  I.  represents  a  glass  tube  of  about  ^ofan 
inch  wide  and  seven  or  eight  inches  long  ;  a  is  a 
wooden  rod  about  ten  inches  long,  called  a  piston 
rod,  with  a  piece  of  leather  wrapped  round  it  at  b, 
the  piston.  After  the  water  in  the  glass  tube  has 
been  made  to  boil  by  the  lamp  c  long  enough  to 
expel  the  atmospheric  air,  introduce  the  piston  a 
little  way  into  the  tube,  and  plunge  the  tube  into 
water,  and  you  will  find  that  the  piston  will  in¬ 
stantly  be  driven  downwards.  Hold  the  tube  over 
the  lamp  again,  and  the  piston  will  be  driven  up¬ 
wards,  and  so  on  as  often  as  you  please,  to  heat 
and  cool  it.  The  reasons  are  these  :  by  plunging 
the  tube  into  cold  water  the  steam  is  suddenly 
condensed,  and  a  vacuum  is  created,  into  which 
the  piston  is  forced  by  the  pressure  of  the  at¬ 
mosphere.  When  the  water  in  the  bulb  resumes  the  pro¬ 
cess  of  boiling,  by  being  replaced  over  the  lamp,  steam 
is  generated  below  the  piston,  which  expands  itself  in  the 
tube  and  forces  the  piston  upwards. 

This  is  “  a  steam  engine”  in  its  simplest  form,  and  you 
will  readily  conceive  that  if  the  piston  rod  is  attached  to 
a  lever  or  wheel,  it  can  communicate  force  and  motion. 

In  the  engine  represented  in  figure  I,  the  piston  is  forced 
upwards  only  by  the  expansive  power  of  the  steam  ;  when 
.he  steam  is  condensed  and  a  vacuum  is  created  below  the 
piston,  it  is  forced  downwards  by  the  pressure  of  the  atmo 


Fig.  I. 


RENDERED  EASY. 


437 


sphere.  This  is  what  is  therefore  called  “an  atmospheric 
engine.”  After  each  stroke  of  the  piston  the  cylinder  has 
to  be  cooled,  in  order  that  the  necessary  condensation  of 
the  steam  may  take  place,  which  occasions  a  great  waste 
of  fuel.  There  is  another  inconvenience  attending  this  en¬ 
gine,  viz.  the  rate  of  the  motion  cannot  be  well  regulated. 

Fig.  II. 


Figure  II.  represents  a  “ double-xvorlring  steam  engine .” 
B  is  a  section  of  the  boiler,  which  is'  provided  with  a  safety- 
valve  b,  the  use  of  which  is  to  allow  the  passage  into  the  at¬ 
mosphere  of  the  steam,  in  case  too  much  should  be  generated 
for  the  safety  of  the  machine.  This  safety-valve  is  regula¬ 
ted  by  the  lever  D  E,  and  the  moveable  weight  D.  Y  U  S  T 
indicate  the  cylinder,  r  the  piston  rod,  and  R  the  piston, 
which  is  filled  in,  or  “  stuffed”  as  it  is  called,  with  wool, 
tow,  felt  or  metal,  in  such  a  way  as  to  be  as  nearly  air  and 
steam  tight  as  possible,  without  creating  too  much  friction 
against  the  sides  of  the  cylinder,  as  the  piston  moves  up 
and  down.  K  is  a  box  stuffed  in  like  manner,  and  for  the 
like  purpose,  through  which  the  piston  rod  passes.  The 
steam  pipe  P  communicates  with  the  boiler,  and  through  it 
the  steam  is  conveyed  from  the  boiler  to  the  cylinder.  This 
pipe,  it  will  be  observed,  is  divided  into  two  branches,  L 
and  M.  This  is  for  the  purpose  of  conveying  the  steam, 
either  above  or  below  the  piston,  according  as  it  is  required 
to  force  the  piston  down  or  up.  Each  branch  is  provided 
with  a  valve  or  a  stop-cock,  by  which  the  communication 
between  the  boiler  and  cylinder  can  be  cut  off  and  opened 
again.  On  the  opposite  side  of  the  cylinder  are  two  similar 
37* 


438 


STEAM  ENGINE 


branches,  O  and  N,  forming,  where  they  unite,  the  “educ* 
tion  pipe”  W,  which  is  connected  with  the  “ condenser ”  C. 
The  branches  O  N  being  each  provided  with  a  valve  or 
etop-coek,  which  are  alternately  opened  and  closed,  and 
used  for  the  purpose  of  discharging  the  steam  which  has 
performed  its  office  into  the  condenser.  The  condenser 
is  kept  constantly  cool  by  surrounding  it  by  a  well  of  cold 
water.  By  tnis  means,  the  discharged  steam,  which  passes 
through  the  eduction  pipe,  is  instantaneously  condensed. 
The  pump  Q  serves  for  the  important  purpose  of  continu¬ 
ally  freeing  the  condenser  of  air  and  water,  and  preparing 
it  for  the  reception  of  the  discharged  steam. 

When  the  machine  is  to  be  set  in  operation,  the  water  in 
the  boiler  13  is  heated  by  the  furnace  F,  and  a  part  of  it  is 
converted  into  steam.  The  four  valves  L,  lYI,  N,  and  0, 
are  then  all  opened,  so  as  to  admit  the  steam  from  the  boiler 
to  pass  both  above  and  below  the  piston,  and  at  the  same 
time  to  admit  of  its  escape  into  the  condenser,  and  thence 
through  tho-pump  Q  into  the  open  air.  This  process,  which 
is  called  “blowing  out  the  engine,”  has  for  its  object  the  ex¬ 
pulsion  of  the  atmosphere  from  every  .part  of  the  machine. 

This  being  done  the  valves  or  stop-cocks  M  and  0  are 
closed,  the  steam  is  then  admitted  through  the  branch  L 
only,  passing  the  valve  or  stop-cock  L,  and  entering  into 
the  cylinder  above  the  piston,  which  it  forces  down  to  tho 
bottom  of  the  cylinder,  and  thus  imparts  the  first  motion  to 
the  engine.  As  the  piston  thus  descends,  the  steam  which 
was  below  it  in  the  cylinder  is  forced  through  the  branch 
N  and  eduction  pipe  W  into  the  condenser,  andbeing  turn¬ 
ed  into  water,  is  drawn  off  by  the  pump  Q.  The  valves 
or  stop-cocks  L  and  N  are  now  closed,  and  M  and  O  are 
at  the  same  time  opened,  upon  which  the  steam  rushes  from 
the  boiler  through  the  steam  pipe  P  and  branch  M  under 
the  piston,  and  forces  it  to  the  top  of  the  cylinder,  and  the 
steam  which  was  above  the  piston  then  passes  through  the 
branch  0  and  eduction  pipe  W  into  the  condenser  in  like 
manner,  and  so  on,  the  opposite  valves  or  stop-cocks  open¬ 
ing  and  shutting,  alternately,  producing  an  alternate  up¬ 
ward  and  downward  motion  in  the  piston  rod,  which  being 
communicated  to  the  machinery,  keeps  it  in  a  continual 
and  regular  motion. 


RENDERED  EASY. 


439 


The  valves  nr  stop-cocks  L,  M,  N,  O,  in  the  branches, 
are  usually  opened  and  shut,  and  the  pump  Q  worked  by 
the  engine,  being  effected  by  levers  connected  with  the  pis¬ 
ton  rod,  which  makes  the  motion  more  uniform  and  regular. 

In  this,  which  is  a  low-pressure  engine,  the  pressure  of 
the  steam  is  averaged  at  fifteen  pounds  at  the  square  inch, 
which  is  equal  to  the  weight  of  one  atmosphere,  and  the 
power  is  proportioned  to  the  surface  of  the  piston  and 
bore  of  the  cylinder.  It  is  generally  calculated  by  the 
power  ot  so  many  horses.  The  power  offthe  engine  may 
be  increased  or  diminished  by  increasing  or  diminishing 
the  size  of  the  piston  and  cylinder,  for  in  proportion  to  the 
pressure  of  the  steam  upon  the  piston,  will  it  be  moved 
up  and  down  with  greater  or  less  force. 

Fig.  III. 


If  the  motion  required  be  rotary,  the  piston  rod  A,  Fig. 
III.,  is  connected  to  one  end  of  a  lever,  whose  fulcrum,  C, 
is  in  the  centre,  and  the  other  end  of  the  lever,  B,  is  con¬ 
nected  with  the  wheel  by  means  of  a  crank,  D. 

The  safety-valve  6,  Fig.  II.,  is  shaped  conically,  and  is 
Kept  in  its  place  by  the  lever  D  E,  charged  with  the  weight 
D.  This  weight  can  be  moved  further  from  or  nearer  to 
the  safety-valve,  according  as  we  wish  the  steam  in  the 
boiler  to  attain  a  greater  or  less  degree  of  elasticity.  Al¬ 
though  it  is  generally  stated  that  in  the  low-pressure  engine 
the  steam  is  used  as  it  is  generated,  at  212°,  which  is  equal 


440 


8TEAM  ENGINE 


to  just  one  atmosphere,  yet  it  is  necessary  to  attach  a 
small  additional  weight  to  the  lever  D  E,  to  increase  the 
elasticity  of  the  steam  in  the  boiler,  to  a  degree  which  en¬ 
ables  it  to  blow  out  with  force  sufficient  to  prevent  the  ad¬ 
mission  of  the  atmosphere  into  the  machine. 

Instead  of  the  valves  and. stop-cocks  above  described  for 
the  admission  and  escape  of  the  steam,  a  single  slide  is 
substituted.  It  consists,  as  may  be  seen  in  fig.  IV.  and  V., 
in  a  slide  S,  which  can  be  moved  up  and  down  from  L  to  M. 
This  is  effected  by  the  levers  M,  N,  0,  and  an  eccentric, 
which  is  moved  by  the  turning  of  the  wheel.  When  the 
slide  is  in  the  position  represented  in  fig.  IV.  the  steam  in 
the  boiler  is  admitted  through  the  steam  pipe  P,  through  the 
branch  q  r,  and  thence  through  the  opening  u  in  the  lower 
part  ol  the  cylinder,  to  force  upwards  the  piston,  while  the 
steam  that  was  above  the  piston  is  discharged  through  the 
passage  a  b  dn  o  e  into  the  condenser.  The  next  turn  oi' 


Fig.  IV 


C 


e 


RENDERED  EAST. 


441 


Fig.  V 


•» 

the  wheel  places  the  slide  S  in  the  position  represented  in 
fig.  Y.  The  communication  being  cut  off,  the  steam  can 
no  longer  pass  through  the  branch  q  r ;  but  it  has  free  ac¬ 
cess  through  the  branch  l  d  b  a  into  the  upper  part  of  the 
cylinder  above  the  piston,  forcing  it  down,  while  the  steam 
which  was  below  the  piston  finds  a  way  opened  for  its  es¬ 
cape  through  the  branch  t  u  r  q  n  o  e  into  the  condenser. 

In  the  “  high  pressure  engine”  the  steam  from  both  above 
and  below  the  piston  is  discharged  directly  into  the  atmo¬ 
sphere  ;  it  therefore  occupies  less  space,  as  it  requires  nei¬ 
ther  condenser,  water-well  nor  air  pump.  But  the  atmo¬ 
sphere  having  access  to  that  surface  of  the  piston  which  is 
*  opposite  to  the  steam,  and  exercising  upon  it  a  pressure 
equal  to  15  pounds  to  the  square  inch,  it  follows,  that  the 
steam  employed  for  this  engine  must  be  confined  until  it 
attains  an  elasticity  that  is  sufficient,  first,  to  overcome  that 
atmospheric  pressure,  and  then  to  drive  the  machinery. 
But  when  the  boiler  and  cylinder  of  the  high-pressure  en- 


442 


STEABI  ENGINE,  ETC. 


gine  are  strong,  a  powerful  pressure  can  be  exercised  with 
a  very  small  volume  of  steam,  but  of  great  elasticity. 

1  here  are  two  hollow  tubes,  each  provided  with  a  stop¬ 
cock,  both  communicating  with  the  boiler.  One  of  these, 
called  the  “steam  gauge,”  communicates  with  the  steam  ; 
and  the  other,  which  communicates  with  the  water,  is 
called  the  “  water-gauge.”  The  use  of  the  steam  and 
water  gauges  is  to  ascertain  if  the  proper  quantity  of  water 
is  in  the  boiler.  When  the  stop-cock  of  the  steam  guage 
is  opened,  if  water  issues,  there  is  too  much  of  that  liquid 
in  the  boiler  ;  if,  when  the  water  gauge  stop-cock  is  open¬ 
ed,  nothing  but  steam  issues,  then  the  water  is  too  low  in 
the  boiler. 

There  is  also  attached  to  some  engines,  a  little  instru¬ 
ment  which  is  called  the  “governor.”  It  consists  of  two 
balls,  each  of  which  is  fixed  upon  the  lower  end  of  a  lever, 
the  upper  end  ot  which  lever  is  loosely  connected  with  an 
upright  shaft  by  a  pin.  The  shaft  is  connected  with  the 
fly  wheel,  from  which  it  receives  its  rotary  motion.  The 
balls,  according  to  the  law  of  centrifugal  forces,  recede 
from  or  approach  towards  the  shaft,  in  the  ratio  of  the 
velocity  of  the  governor-shaft  and  flywheel.  The  gover¬ 
nor  is  also  connected,  by  appropriate  machinery,  with  a 
valve  in  the  steam  pipe,  which  valve  it  opens  or  shuts;  so 
that  it  the  machine  goes  faster  than  it  ought  to  do,  the 
valve  of  the  steam  pipe  gently  closes,  and  shutting  ofi'  a 
portion  ot  the  steam  from  the  cylinder,  retards  the  motion  ; 
on  the  other  hand,  if  the  machine  goes  too  slow,  the  shaft 
of  the  governor  revolves  with  less  velocity,  the  balls  being 
less  acted  upon  by  the  centrifugal  force,  descend  and  ap¬ 
proach  the  shaft,  and  by  means  of  the  machinery  afore¬ 
said,  the  valve  of  the  steam  pipe  gently  opens  and  more 
steam  is  allowed  to  pass  from  the  boiler  to  the  cylinder. 
Thus  does  the  engine  regulate  its  own  velocity,  makin"  it 
more  uniform. 


manager’s  assistant. 


448 


TIIE 

MANAGERS  AND  OVERSEERS’  ASSISTANT; 

CONTAINING  THE 

ART  OF  CALCULATION  IN  A  COTTON  MILL, 

Through  all  its  various  operations,  from  the  Raw  Material  into  Yarn 
and  Cloth.  Arranged  in  a  concise  and  simple  manner.  By  an 
Operative  Spinner. 


INTRODUCTORY. 

It  is  presumed,  that  this  small  treatise  will  be  rendered 
valuable,  not  only  to  Overseers  and  Managers ,  but  to 
every  one  who  may  ft  >1  desirous  to  attain  a  situation  as 
manager  or  overseer  in  a  cotton  mill.  The  different 
branches  are  illustrated  with  simplicity  and  perspicuity,  and 
may  be  easily  understood  by  those  persons  who  have  but 
little  time  to  devote  to  study.  An  individual  who  fully 
comprehends  the  following  rules,  may  discharge  the  va¬ 
rious  duties  attached  to  an  official  situation  in  a  cotton-mill, 
with  ease  and  credit  to  himself — and  to  the  entire  satis¬ 
faction  of  his  employers. 


MANAGER’S  ASSISTANT. 

To  find  the  counts  of  Cotton,  at  the  end  of  every  operation 
from  the  raw  material  into  Yarn. 

Suppose  a  lap  8  feet  long  weighs  one  pound  two  ounces, 
allowing  the  two  ounces  to  waste  in  going  through  all  its 
operations. 

RULE. 

840  yards  being  in  one  hank,  weigh  one  pound,  conse- 
quently,  there  must  be  one  hank  in  the  pound,  that  being 
multiplied  by  3  brings  it  into  feet,  and  divided  by  8  feet, 
will  be  the  315th  part  of  a  hank 


441 


mahager’s  assistant. 


EXAMPLE. 

840  yards  in  one  hank. 
8  feet  in  one  yard. 

8)2520 


315  Answer  required. 

To  find  the  counts  after  going  llirougn  a  earning  engine . 

Suppose  a  draught  of  a  carding  engine  to  be  78J,  and 
a  lap  before  going  through  be  the  315th  part  of  a  hank. 

RULE. 

Reduce  the  into  fourth,  and  divide  that  product  I 
315,  and  it  will  be  one-fourth  of  a  hank. 

EXAMPLE. 

78f 

4 


315)315(1  that  is  -J-  of  a  hank. 
315 


To  find  the  draught  of  a  carding  engine. 

Suppose  the  diamater  of  the  doffer  cylinder  be  18  inches 
with  a  wheel  upon  the  doffer  shaft  of  30  teeth,  and  work 
into  another  upon  the  side  shaft  of  35  teeth,  on  the  other 
end  ot  the  side  shaft  is  a  20  that  works  into  a  wheel  upon 
the  feed  rollers  of  a  150  teeth,  and  the  diameter  of  the 
feed  roller  is  2  inches.  The  draught  is  required. 

RULE. 

Multiply  the  30  on  the  doffer  end,  by  the  20  on  the  side 
shaft  that  works  in  the  wheel  upon  the  feed  roller,  then  by 
the  2  inches  the  diameter  of  the  feed  roller  for  a  divisor. 
Ihen  multiply  the  150  upon  the  feed  roller  by  18  inches 
the  diameter  of  the  doffer ;  then  by  the  35  on  the  side 
shaft  for  a  dividend,  and  the  draught  will  be  78|. 


manager’s  assistant. 


446 


EXAMPLE. 


30  150 

20  is 


600  1200 

2  150 


Divisor,  12  00  2700 

35 


13500 

8100 


945  00(78^-  Answer  required. 
84 


105 

96 


9 

To  find  in  what  proportion  a  carding  engine  shoidd  car  a 
to  furnish  the  mules  with  a  proper  quantity  of  prepara¬ 
tion  in  changing  from  one  count  to  another. 

Suppose  a  pair  of  mules  be  spinning  80’s  weft,  with  85 
turns  in  a  certain  length  of  lap  going  up  at  the  carding  en¬ 
gine,  weighing  9  lbs.,  and  the  mule  changing  to  90’s  twist, 
with  105  turns  :  the  lap  of  the  same  length  is  required. 

RULE. 

Niuety’s  twist  requiring  a  lighter  lap  than  80’s  weft, 
and  105  turns  require  a  lighter  lap  than  85  turns  :  multiply 
the  105  by  90’s  for  a  divisor,  and  the  85  turns  by  80’s, 
then  by  9  pounds,  the  weight  of  the  lap  for  a  dividend. 
The  answer  will  be  nearly  6  lb.  7£  oz. 


38 


446 


manager’s  assistant. 


EXAMPLE 

80 

85 

90  ■ 

105 

105 

85 

90 

80 

6S00 

9450  Divisor. 

9 

61200(6  lb.  7  oz.  Answer. 
56700 


4500 

16  oz.  in  1  pound. 


27000 

4500 


72000(7  oz. 
66150 


8950 

To  fini  the  counts  after  going  through  a  drawing  frame. 

Suppose  the  carding  to  be  of  |  of  a  hank,  and  goes 
through  3  boxes  of  drawings,  and  puts  up  6  ends  at  each 
box,  and  the  draught  of  the  first  box  to  be  5J,  and  the  sc 
cond  to  be  6,  and  the  third  box  to  be  six  and  six  twenty, 
thirds.  1 

RULE. 

Multiply  the  doubling  at  each  box  one  into  another  for 
a  divisor,  and  the  draught  of  each  box  one  into  another 
for  a  dividend,  and  the  answer  will  be  one-fourth  of  a 
hank,  alter  going  through  the  three  heads  of  drawing,  con¬ 
sequently,  nothing  here  is  gained  but  doubling. 

The  draught  of  the  first  box  and  the  doubling,  must  bo 
brought  into  fourths,  the  draught  of  the  last  box  and  the 
doubling  brought  into  twenty.thirds. 


MANAGER’S  ASSISTANT. 


447 


EXAMPLE. 

1st  box  6  ends 

24 

23  1st  box  5f 

6 

6  ends,  “  6 

2d,  «  6  « 

144 

138 

138 

144  3d  box  6^ 

3d,  «  6  “ 

1152 

552 

% 

432 

552 

144 

138 

Divisor, 

19S72 

^1 9872 1 ( 1  or  i  °f  a  hank. 

r°  find  the  draught  oj  the  last  box  to  gain  nothing  but 

doubling. 

Suppose  3  heads  of  drawing  have  6  ends  put  up  at  each 
head,  and  the  draught  of  the  first  be  5f,  and  the  draught 
of  the  second  6  :  the  draught  of  the  last  box  is  required. 

RULE. 

Multiply  the  draught  of  the  first  and  second  box  for  a 
divisor;  then  multiply  the  doubling  of  three  boxes  one  into 
another  for  a  dividend,  and  the  draught  of  the  last  box  wil' 

be  t^j-. 

Note.  The  draught  of  the  first  box  must  be  brought 
into  fourths,  consequently,  the  dividend  must  be  brought 
into  fourths  also. 

EXAMPLE, 


5*  6 

4  6 


23  36 

6  6 


Divisor,  138  216 

4 


864 

828  (6^.  Answer. 


36 


448 


manager’s  assistant. 


To  find  the  draught  of  a  drawing  frame  with  '4  rollers. 

When  a  drawing  frame  has  4  rollers,  there  will  be  3 
draughts.  The  first  draught  1£,  the  second  roller  2  of  a 
draught.  The  draught  of  the  front  roller  is  required,  al¬ 
lowing  the  whole  of  the  draughts  to  be  9. 

RULE. 

Multiply  the  first  draught  by  1^-  by  the  second  2,  and 
divide  the  whole  of  the  draughts  that  is  9  by  that  product, 
and  the  draught  of  the  first  roller  will  be  3. 


Divisor, 


EXAMPLE. 

3)9 


3  Answer  required. 


To  find  the  counts  when  the  last  box  drawing  has  gone 
through  a  stubbing  frame. 

.  Suppose  the  last  box  drawing  be  f  of  a  hank,  and  go  up 
single  at  a  slubbing  frame,  with  a  20  pinion  wheel  on  the 
coupling  shaft,  a  60  top  carrier,  a  40  back  roller  wheel,  and 
a  30  change  wheel  :  the  counts  are  required. 

RULE. 

Multiply  the  20  pinion  wheel  by  the  30  change  wheel 
for  a  divisor  ;  then  multiply  the  60  top  carrier  by  the  40 
back  roller  wheel  for  the  dividend,  and  the  draught  will  be 
4,  consequently  will  be  one  hank  in  the  pound. 

EXAMPLE. 

30  60 

20  40 


Divisor,  6|  00  24  J00 

24  (4  draughts,  or  1  hank  in 

the  pound.  Answer  required. 

To  find  the  change  iohcel  when  the  last  box  drawing  has 
gone  through  a  slubbing  frame. 

.  Suppose  the  last  box  drawing  be  -J-  of  a  hank,  and  go  up 
B ingle  at  the  slubbing  frame  with  a  20  pinion  wheel  on  the 
front  roller,  and  the  top  carrier  60,  and  the  back  roller 
wheel  40,  and  the  draught  to  be  4  :  the  change  wheel  is 
required. 


manager’s  assistant. 


449 


RUl  E. 

Multiply  the  20  jpon  the  front  roller,  by  the  draught  4 
loi  a  divisor,  and  the  top  carrier  60,  by  the  back  roller  wheel 
40,  for  the  dividend,  the  change  wheel  required  will  be  30 

EXAMPLE. 

20  60 

4  40 


Divisor,  8|0  2400 

24  (30  Answer. 


0 

To  find  the  counts  after  going  through  a  roving  billy. 

Suppose  a  bobbin  of  one  hank  be  drawn  into  a  roving 
and  put  up  two  ends,  with  a  20  pinion  wheel  and  an  80 
top  carrier,  and  a  60  back  roller  wheel,  and  a  30  change 
wheel :  the  number  of  hanks  of  the  roving  is  required. 

RULE. 

Multiply  the  20  pinion  wheel  by  the  2  ends  put  up  at  the 
back.  Then  by  the  30  change  wheel  for  a  divisor.  Then 
multiply  the  80  top  carrier  by  the  60  back  roller  wheel  foi 
a  dividend,  and  the  roving  required  will  be  4  hanks. 

EXAMPLE. 

20  80 

2  60 


40  4800 

30  4800  (4  hanks  the  answer. 

Divisor,  1200 

To  draiv  a  bobbin  into  a  roving. 

Suppose  a  bobbin  of  one  hank  be  drawn  into  4,  and  go 
up  double  at  the  billy,  with  a  20  pinion  and  an  80  top  car¬ 
rier,  and  a  60  back  roller  wheel.  The  change  wheel  is 
required. 

RULE. 

Multiply  the  pinion  wheel  by  the  2  ends  put  up,  and 
then  by  the  4  hanks  roving  for  a  divisor.  Then  multiply 
the  80  top  carrier  by  the  60  back  roller  wheel*for  the  divi¬ 
dend,  and  the  change  wheel  required  will  be  30. 

38*  2  D 


450 


manager’s  assistant. 


Divisv, 


EXAMPLE, 

20 

80 

2 

60 

40 

480|  0 

4 

48 

160  : 

0 

'30  Answer. 


To  find  the  draught  of  a  frame  with  two  headshaving  hit 
draught  oj  the  first  head  given  to  answer  the  purpose  o] 
both  a  stubbing  frame ,  and  a  roving  billy. 

Suppose  the  last  box  drawing  be  of  *  of  a  hank,  and  go 
up  double  at  a  frame  with  two  heads,  and  be  drawn  into  a 
four  hank  roving,  and  the  draught  of  the  first  head  be  5. 
The  draught  of  the  second  head  is  required. 

RULE. 

The  last  box  drawing  being  |  of  a  hank,  and  going  up 
double,  -J-  ol  a  hank,  that  multiplied  by  4  hanks  wanted, 
and  divided  by  the  draught  of  the  first  head,  that  is  5  ; 
then  the  draught  of  the  second  head  which  is  required, 
will  be  6f .  n 

EXAMPLE. 

S 

4 


5)32 


6f  Answer. 

To  find  the  number  of  stretches  upon  a  set  of  rovings. 

Suppose  the  front  roller  of  a  roving  billy  makes  18  revo¬ 
lutions  in  one  stretch,  with  a  worm  upon  the  coupling  shaft 
that  drives  a  wheel  of  30  teeth,  and  a  worm  upon  the 
same  shaft  with  the  30  wheel,  that  drives  a  bell  wheel  with 
120  teeth.  Ihe  number  of  stretches  is  required,  allow, 
ing  the  bell  wheel  to  go  once  round. 

RULE. 

Multiply  the  120  by  the  30  for  a  dividend,  and  divide 
by  the  IS,  that  is,  the  revolutions  of  the  front  roller,  and 
the  number  of  stretches  upon  the  roving  will  be  200. 


manager’s  assistant. 


451 


EXAMPLE. 

120 

30 


18)3600(200  stretches  the  answer. 

To  find  the  counts  ajter  going  through  a  mule. 

Suppose  a  roving  of  4  hanks  be  drawn  into  yarn  with  a 
20  pinion  wheel,  an  80  top  carrier,  a  60  back  roller  wheel, 
a  30  change  wheel,  and  the  length  of  the  stretch  put  up 
60  inches,  and  the  length  of  the  yarn  turned  out  from  the 
rollers  53  inches.  The  number  of  hanks  is  required. 

RULE. 

Multiply  the  pinion  20  by  the  change  wheel  30,  and  the 
product  by  53  inches,  that  the  rollers  turn  out  for  a  divi¬ 
sor  ;  multiply  the  80  top  carrier  by  the  60  back  roller 
wheel,  and  by  the  60  inches  put  up  ;  then  by  the  4  hanks 
roving  for  the  dividend,  and  the  answer  will  be  36j-f . 

EXAMPLE. 

80 


4900 

60 


288000 

4 


)1 152000  (36^-f  Answer. 
95400 


198000 

190800 


7200 

To  find  the  turns. 

Suppose  a  thread  of  yarn  requires  30  revolutions  of  the 
spindles  per  inch,  and  put  up  60  inches  of  a  stretch,  and 
the  spindles  make  20  revolutions  for  one  turn  of  the  rim  : 
the  number  of  turns  is  required. 


20 

30 


600 

53 


1800 

3000 


Divisor,  31800 


452 


manager’s  assistant. 


Rule.  Multiply  the  60  inches  put  up  by  the  30  revolu¬ 
tions  required  per  inch,  and  divide  by  20  the  number  of 
revolutions  of  the  spindle  for  one  turn  of  the  rim,  and 
the  number  of  turns  required  will  be  90. 

EXAMPLE. 

60 

30 


2|0)18010 


90  Answer. 

To  find  n  wheel  to  pul  on  the  bottom  of  the  long  driver,  tc 
make  the  rollers  turn  out  a  certain  number  of  inches, 
in  a  certain  number  oj  turns. 

Suppose  the  rollers  turn  out  53  inches  in  55  turns,  with 
a  53  wheel  on  the  rim  shaft,  a  55  wheel  on  the  top  of  the 
long  driver,  102  upon  the  coupling  shaft,  and  the  circum¬ 
ference  of  the  front  roller  be  3  inches  :  the  wheel  on  the 
bottom  of  the  long  driver  is  required. 

RULE. 

Multiply  the  53  wheel  on  the  rim  shaft  by  the  55  turns, 
and  by  the  3  inches,  the  circumference  of  the  front  roller 
for  a  divisor.  Multiply  the  55  on  the  top  of  the  long  dri¬ 
ver  by  the  53  inches  the  rollers  turn  out,  then  by  the  102 
on  the  coupling  shaft  for  the  dividend,  and  the  wheel  re- 


quired  will  be  34. 

EXAMPLE. 

53 

55 

55 

53 

265 

165 

265 

275 

2915 

2915 

3 

102 

Divisor 

8745 

5830 

2915 

297330(34  Answer. 
26235 


34980 

34980 


manager’s  assistant. 


45* 


To  find  a  wheel  to  put  upon  the  bottom  of  the  short  driver 
to  draw  a  carriage  out  a  certain  number  oj  inches,  in 
a  certain  number  of  turns. 

Suppose  a  carriage  to  be  brought  58  inches  in  55  turns, 
with  a  20  upon  the  rim  shaft,  a  70  upon  the  top  of  the 
short  driver,  a  100  scrall  wheel,  and  the  circumference  of 
the  scrall  18  j\  inches  :  the  wheel  upon  the  bottom  of  the 
short  driver  is  required. 

RULE. 

Bring  18^^-  into  llths,  and  multiply  that  by  55  turns, 
and  by  the  20  upon  the  rim  shaft  for  a  divisor ;  then  mul¬ 
tiply  the  58  inches  by  the  70  wheel  on  the  top  of  the  short 
driver,  then  by  the  100  scrall  wheel,  and  reduce  that  into 
llths  for  the  dividend,  and  the  wheel  on  the  bottom  oi 
the  short  driver  will  be  20. 


EXAMPLE. 


18fr 

58 

11 

70 

203 

4050 

55 

100 

1015 

406000 

1015  • 

11 

11165 

4466000 

20 

4466000 

Divisor,  223300 

(20  Answer. 


To  find  the  number  of  hanks  of  the  roving  from  the  nunu 
her  of  hanks  of  the  mule  in  spinning. 


Suppose  a  pair  of  mules  be  spinning  44’s  weft  and  put 
up  60  inches,  and  the  carriage  gains  from  the  rollers  9 
inches,  with  a  20  on  the  coupling  shaft  or  pinion  wheel, 
and  a  100  top  carrier,  a  30  change  wheel,  a  50  back  roller 
1  wheel.  The  number  ©f  hanks  of  the  roving  is  required. 


454 


manager’s  assistant 


RULE. 

Multiply  the  40  hanks  by  the  9  inches  the  carriage 
gains  and  dmde  by  ^  60  inches  put  up,  it  will  show 
that  6  hanks  are  altered  by  the  gaining  of  the  carriage, 
and  6  hanks  subtracted  from  the  40  hanks,  34  will  re¬ 
main  ;  then  multiply  the  34  by  the  pinion  wheel  20,  and 
by  the  change  wheel  30  for  a  dividend,  and  multiply  the 
top  earner  100  by  the.50  back  roller  wheel  fo  a  di/isor 
and  the  roving  required  will  be  4 


example. 

40 

40 

9 

6 

6,'0)36|0 

34 

20 

6 

6S0 

30 

100 

20400 

50 

20000 

Divisor,  5000 

400 

To  change  from  one  count  to  another  without  changing 

Ike  roving. 

D  t 

noundwfth  \rVf  mU,!S  bf  spinnin£  40  hanks  ^  the 
P°“?d  •  1  36  ch?Dg®  wheel>  and  has  ‘0  change  to  60 
hanks  in  the  pound  :  the  change  wheel  is  required. 

rule. 

As  60’s  will  require  a  less  change  wheel  than  40’s,  con¬ 
sequently,  the  40  and  36  must  be  multiplied  together  for  a 

,“iu  bo  ir hy  *• 6o>  and  ^  *“*•  ^  - 


i 


manager’s  ASSISTANT. 


466 


EXAMPLE. 

As  60  :  40  36 
40 


6|0)144|0 


'  24 

ro  change  from  one  count  to  another ,  when  the  change 
wheel  and  roving  is  required  to  be  altered. 

Suppose  a  pair  of  mules  to  be  spinning  40’s  with  a  4 
hank  roving,  and  a  30  change  wheel,  and  ^altered  to  60’s,  ■ 
with  a  7  hank  roving  :  the  chauge  wheel  is  required. 

RULE. 

Multiply  the  60  by  the  4  hank  roving  for  a  divisor  ; 
then  multiply  the  40  by  the  7  hanks  roving,  and  that  by 
the  30  change  wheel  for  the  dividend,  and  the  change 
wheel  required  will  be  35. 

EXAMPLE. 

40  —  4  —  30 
60  —  7  — 


60  40 

4  7 


Divisor,  24  JO  280 

30 


840J0  (35  Answer. 

72 

120 

120 

/ 

To  find  the  circumference  of  a  scroll  to  draw  a  carriage 
out  a  certain  number  of  inches,  in  a  certain  number 
oj  turns. 

Suppose  a  carriage  be  brought  out  58  inches  in  55  turns, 
with  a  20  wheel  upon  a  rim  shaft,  a  70  upon  the  top  of  the 


456 


manager’s  assistant. 


short  driver,  a  20  on  the  bottom,  and  a  100  the  scroll 
wheel ;  the  circumference  of  the  scroll  is  required. 

RULE. 

Multiply  the  55  by  the  20  upon  the  rim  shaft ;  then  by 
the  20  at  the  bottom  of  the  short  driver  for  a  divisor  ; 
multiply  the  58  inches  by  the  70  on  the  top  of  the  short 
driver,  then  by  100  on  the  scroll  shaft  for  the  dividend, 
and  the  circumference  of  the  scrall  will  be  lS,5^. 

EXAMPLE. 

55  58 

20  70 


1100  4060 

20  100 


Divisor,  22J000  )406000  (18ft  Answer. 

22 


1S6 
176  ^ 


10 

To  find  the  circumference  of  a  mandosa  pully,  to  draw  out 
a  carriage  a  certain  number  of  inches,  in  a  certain  num¬ 
ber  of  turns. 

Suppose  a  carriage  be  brought  out  58  inches  in  55  turns, 
and  a  wheel  on  the  rim  shaft  of  53  teeth,  and  a  wheel  on 
the  top  of  the  long  driver  of  55  teeth,  a  34  on  the  bottom 
of  the  long  driver,  that  works\into  a  wheel  on  the  coupling 
shaft  of  100  teeth,  aud  a  wheel  of  30  teeth  on  the  same 
shaft  that  works  in  one  oh  the  mandosa  shaft  of  250  teeth, 
the  circumference  of  the  mandosa  pully  is  required. 

RULE. 

Multiply  the  55  turns  by  the  53  on  the  rim  shaft,  by  34 
on  the  bottom  of  the  long  driver,  by  30  on  the  coupling 
shaft  for  a  divisor  ;  multiply  55  on  the  top  of  thb  long  dri¬ 
ver  by  100  on  the  coupling  shaft,  by  260  the  mandosS 


manager’s  assistant. 


457 


wheel,  the  58  inches  for  the  dividend,  and  the  circumfer¬ 
ence  of  the  mandosa  pully  will  be  27  inches,  89  of  a  deci¬ 
mal,  or  nearly  28  inches. 


55 

53 

165 

275 

2915 

34 

11660 

8745 

99110 

30 


29733j00 


EXAMPLE. 

55 

100 


5500 

260 

330000 

11000 

1430000 

58 

11440000 

7150000 

)829400[00  (27—89 

59466 


234740 

206131 

266090 

237864 

282260 

267597 


or  nearly  28  inches. 


14663 

To  draw  a  roving  into  yarn. 

Suppose  a  thread  of  36|f  be  drawn  from  a  4  back  rov¬ 
ing,  with  a  twenty  pinion  wheel,  and  an  80  top  carrier,  a 
60  back  roller  wheel,  and  the  number  of  inches  put  up  60, 
and  the  number  of  inches  turned  out  of  the  rollers,  53 
the  change  wheel  is  required. 

39 


468 


manager’s  assistant. 


RULE. 

Reduce  the  36^-f  into  53rds,  then  multiply  the  product 
by  the  pinion  wheel  20,  and  by  the  63  inches  the  rollers 
turn  out  for  a  divisor  ;  multiply  the  80  top  carrier  by  the 
60  back  roller  wheel,  and  by  the  60  inches  put  up,  then  by 
the  4  hank  roving;  reduce  those  products  into  53rd.s  for 
the  dividend,  and  divide  it  as  in  whole  numbers,  and  the 
change  wheel  required  will  be  30. 

\ 

EXAMPLE. 

36£f  80 

110  60 

181  - 

- :  4800 

1920  60 

20  - 

-  288000 

3S400  4 

53 - 

— - -  1152000 

113200  63 

192000  _ _ 

-  3456000 

2035200  Div.  5760000 


)G10560j00  (30  Answer. 

61056 

To  find  a  wheel  to  put  on  the  middle  roller,  for  the  middle 
roller  to  draw  from  the  back  roller  6  into  7. 

Suppose  the  diameter  of  the  back  roller  be  £  and  the 
diameter  of  the  middle  roller  to  be  |  of  an  inch,  and  the 
wheel  upon  the  back  roller  be  24  :  the  wheel  on  the  mid¬ 
dle  roller  is  required. 

RULE. 

Multiply  the  24  on  the  back  roller  by  the  £  of  the  mid- 
die  roller,  and  divide  it  by  the  £  of  the  back  roller,  and  the 
wheel  required  to  take  it  up  as  the  back  roller  delivered  it, 
will  be  21  ;  that  multiplied  by  6.  and  divided  by  7,  will 
show  that  the  wheel  required  on  the  middle  roller  to  draw 
6  into  7,  will  be  18. 


manager’s  assistant. 


469 


EXAMPLE. 

24 

7 

8)168 

21 

6 

7)126 

18  Answer  required. 

To  find  the  draught  of  a  male. 

Suppose  the  pinion  wheel  upon  the  coupling  shaft  be 
20,  the  top  carrier  120,  change  wheel  38,  back  roller  wheel 
64,  and  the  diameter  ot  the  back  roller  -£•  of  an  inch,  and 
the  front  roller  -§■ :  the  draught  is  required. 

RULE. 

Multiply  the  change  wheel  38  by  the  pinion  wheel  20, 
then  f  diameter  of  the  back  roller  for  the  divisor  ;  then 
multiply  the  top  carrier  120  by  the  back  roller  wheel  64, 
then  b  v  the  diameter  of  the  frout  roller  f  for  the  dividend, 
nnd  the  draught  will  be  9-^%-. 

EXAMPLE. 


38  120 

20  54 

760  480 

7  600 


Divisor,  6320  6480 

8 


61840  (9^  Answer. 
47880 


8960 


460 


manager’s  assistant. 


To  find  the  number  of  revolutions  of  the  spindles  for  every 

inch  of  yarn. 

Suppose  a  thread  of  yarn  to  be  spun  with  90  turns,  and 
20  revolutions  of  the  spindle  for  one  turn  of  the  rim,  and 
puts  up  60  inches  :  the  number  of  revolutions  per  inch  is 
required. 

RULE. 

Multiply  the  90  turns  by  the  20  revolutions  of  the  spin¬ 
dle,  and  divide  by  60  inches  put  up,  and  the  number  of 
revolutions  per  inch  will  be  30. 

EXAMPLE. 

90 

20 


60[0)1S0J0 


30  Answer. 

'To  find  the  counts  of  yarn,  without  the  assistance  of  a 
compendious  table. 

Suppose  one  lea  or  120  yards  weigh  25  grains  :  tho 
counts  are  required. 

RULE. 

Seven  thousand  grains  being  one  pound,  and  7  leas  one 
hank,  and  a  lea  being  a  seventh  part  of  a  hank,  and 
weighing  25  grains,  1000  grains  must  be  divided  by  25 
grains,  and  the  counts  required  will  be  40’s  ;  and  if  2  leas 
be  taken,  2000  must  be  divided  by  what  it  weighs,  and 
so  on  up  to  7  leas. 

EXAMPLE. 

25)1000  (40  Answer. 

100 

To  find  in  what  portion  to  put  twist  in  yarn  per  inch ,  in 
changing  from  one  count  to  another. 

Suppose  a  pair  of  mules  am  spuming  40’s  twist,  with 
22£  revolutions  of  the  spindl«  per  inch,  aud  change  to 
DO’s  twist :  the  number  of  revolutions  of  the  spindle  per 
inch  is  required. 


manager’s  assistant. 


461 


RULE. 

Add  2-*-  revolutions  of  the  spindle  for  every  10  hanks, 
and  it  shows  the  number  of  revolutions  required. 

Note.  90’s  being  50  hanks  finer  than  40’s,  multiply  2£ 
by  5  and  it  will  give  12^-,  that  added  to  the  22£  will  show, 
that  90’s  require  35  revolutions  per  inch. 

40’s  weft  requiring  16^-  revolutions  per  inch,  and  12£ 
added  to  that,  shows  that  90’s  weft  require  29  revolutions. 

I 

EXAMPLE. 


Tivist , 

22.5 

2  { 5 

12.5 

5 

35.0 

12!5 

Wejt, 

16.5 

25 

12.5 

5 

29.0 

12.5 

To  find  the  number  of  stretches  upon  a  cop. 

Suppose  a  cop  run  10  leas  with  80  turns  of  the  reel  in 
one  lea,  and  54  inches  in  one  turn,  and  the  number  of 
inches  the  mule  puts  up  is  60  :  the  number  of  stretches  is 
required. 

RULE. 

Multiply  that  10  leas  by  the  80  turns  of  the  reel  in  one 
lea,  then  by  54  inches  in  one  turn,  and  divide  by  the  60 
inches  put  up,  and  the  number  of  stretches  will  be  720. 

EXAMPLE. 

10 

80 

800 

54 

6|0)4320|0 


39* 


720  Answer. 


462 


manager’s  assistant. 


To  find  the  average  counts  of  a  set  of  Cops. 

Suppose  a  mule  have  420  spindles,  and  one  cop  run  10 
leas,  and  the  whole  set  weighs  15  pounds,  the  average 
counts  are  required. 

I 

RULE, 

Multiply  the  420  spindles  by  10  leas  for  the  dividend, 
then  multiply  the  15  pounds  by  7  leas  in  one  hank  for  a 
divisor,  and  the  average  counts  will  be  40’s. 

EXAMPLE. 

15  420 

7  10 

Divisor -  - - 

105  4200  (40  Ans. 

420 


To  find  the  Weight  of  a  fVaip. 

Suppose  a  warp  270  yards  long,  with  33  beers,  and  60 
ends  to  each  beer,  and  the  number  of  hanks  be  34’s  twist 
the  weight  of  the  warp  is  required. 

RULE. 

Multiply  the  270  by  33  beers,  then  by  60  ends  in  each 
beer,  that  will  show  the  number  of  yards  the  warp  con. 
tains  ;  then  divide  the  yards  by  S40,  and  it  will  show  the 
number  of  hanks  it  contains  ;  then  divide  the  number  of 
hanks  by  34  hanks  in  the  pound,  and  it  will  show  the  num¬ 
ber  of  pounds;  then  multiply  the  remainder  by  16,  and 
divide  by  34,  as  before,  and  the  weight  of  the  warp  will 
be  18  pounds  11  ounces  r 


manager’s  assistant.  468 


EXAMPLE. 


lbs.  oz. 

270  036(18  11 

33  34 


810  296 

810  272 

8910  24 

60  16 

84j0)53460j0(34  144 

504  24 

306  384(11 

352  34 

540  44 

504  34 

36  10 


To  find  the  Weight  of  Weft  to  fill  a  l  Varp. 


Suppose  a  warp  of  270  yards  long  be  wove  into  cloth, 
and  allowing  30  yards  to  mill  up  in  the  weaving  and  other 
waste,  and  the  breadth  of  the  cloth  29  inches,  with  80  picks 
in  each  inch,  and  the  number  of  hanks  of  the  weft  be  34- 
in  the  pound,  the  weight  of  the  weft  is  required. 

RULE. 

Subtract  30  yards  from  the  270  yards,  and  240  remain; 
‘hat  multiplied  by  29  inches,  the  breadth  of  the  cloth,  then 
by  80  picks  per  inch,  it  will  show  the  number  of  yards  ; 
‘.hen  divide  by  840,  and  it  will  bring  it  into  hanks  ;  then 
divide  the  hanks  by  34  in  the  pound,  and  it  will  be  19 
pounds;  then  multiply  the  remainder  by  16,  and  divide 
by  34  as  before :  it  will  show  the  weight  of  weft  required 
will  bo  19  lbs.  7  oz. 


464  manaorr’s  ass 

ISTANT. 

EXAMPLE 

• 

270 

30 

240 

29 

lbs.  oz. 

2160 

662(19  7 

480 

34 

6960 

322 

80 

306 

84|0)55680|0(34 

16 

304 

16 

528 

96 

604 

16 

240 

256(7 

168 

238 

72  • 

18 

lo  put  a  pair  of  mules  in  a  good  working  condition ,  whin 
the  roller  beam ,  spindle  box,  Jailer,  and  altogether  is  out 

oj  ol  der. 

Set  the  roller  beam  straight,  then  with  a  guage  sot  the 
carriage  strips  all  at  one  distance  from  the  bottom  centre 

of  the  front  roller  ;  when  that  is 

done,  theu  with  a  level 

set  all  the  carriage  strips  at  the  front  of  the  bevel  intend¬ 
ed.  Set  all  the  ends  ot  the  spindle  box  bottoms  at  ouo 
distance  to  the  carriage  ends.  String  a  line  along  the  bot¬ 
tom^  of  the  spindle  box,  and  set  the  line  about  a  quarter  of 
an  inch  from  touching  at  each  end  :  the  best  manner  of 
doing  this  is  by  driving  a  small  nail  at  each  end  of  the 
spindle  box,  and  lapping  the  line  around  them,  and  with 
the  squaring  bands  square  tho  carriage  so  that  the  line  ia 


manager’s  assistant. 


465 


clear  in  the  middle  and  the  ends  ;  and  put  in  the  bevel 
intended  for  the  spindle  at  each  end,  and  string  a  line 
along  the  top  of  the  spindles  also,  and  set  (hem  straight. 
Then  set  the  fuller  and  the  stops  at  the  back  to  the  dis¬ 
tance  intended  the  spindles  should  be  from  the  rollers. 

A  TABLE 

Snoxving  the  requisite  number  of  revolutions  oj  the  spindle 
for  every  inch  of  yarn,  of  txvist  and  weft ,  beginning  al 
40’s,  and  going  tip  to  200’s. 

As  no  proper  calculation  can  be  made  on  account  of  the 
variations  of  the  cotton,  but,  by  observing  the  following 
Table,  no  person  will  be  led  into  an  error. 


Twist. 

Revolutions. 

Weft. 

Revolutions. 

40 

22* 

40 

16* 

50 

25 

50 

IS 

60 

27* 

60 

21* 

70 

30 

70 

24 

80 

32i 

80 

26i 

90 

35 

90 

29 

100 

374 

100 

31* 

110 

40 

110 

34 

120 

42* 

120 

361 

130 

45 

130 

39 

140 

47^ 

140 

411 

150 

50 

150 

44 

160 

52i 

160 

46i 

170 

55 

170 

49 

180 

'  571 

180 

51i 

190 

60 

190 

54 

200 

62i 

200 

56* 

->  tr, 

! 


466 


manager’s  assistant. 


A  TABLE 


Dwt. 

Grains 

Hanks. 

Dwt. 

Grains 

Hanks. 

83 

8 

X 

4 

7 

13 

24 

55 

13 

X 

8 

7 

5 

21 

41 

1G 

X 

2 

6 

22 

8 

3 

33 

8 

X 

8 

6 

16 

3-L 

27 

18 

X 

4 

6 

9 

8 

3f 

23 

20 

19 

20 

x 

8 

1 

6 

6 

.4 

22 

3£ 

34 

18 

12 

H 

6 

17 

16 

16 

if 

5 

13 

8 

3f 

15 

3 

A  8 

5 

9 

31- 

13 

21 

H 

5 

5 

4 

12 

19 

1^ 

8 

5 

0 

4-L 

11 

21 

n 

4 

21 

8 

44- 

11 

10 

2 

10 

H 

2 

4 

4 

18 

15 

4A 

44 

9 

19 

2* 

4 

12 

44 

9 

6 

2? 

4 

9 

44 

8 

18. 

2f 

4 

6 

4 

41 

8 

6 

** 

4 

4 

5 

7 

22 

2| 

HYDROMETERS. 


487 


HYDROMETERS. 


The  following  Table  shows  the  correspondence  between 
Beaume,  Twedale,  and  specific  gravity  ;  and  no  doubt 
will  prove  useful  to  dyers,  colourers,  calico  printers,  and 
bleachers. 


twedale’s  hydrometer. 

This  instrument  is  in  form  and  principle  the  same  as 
Beaume’s  hydrometer  for  salts,  except  in  the  giadation.  It 
takes  cognizance  only  ol  liquids  whose  specific  gravity 
exceeds  that  of  water.  Its  zero  is  water  at  60  degrees, 
and  the  space  between  and  1.S50  (formerly  regarded  as 
the  specific  gravity  of  concentrated  sulphuric  acid,)  is  di¬ 
vided  into  170  equal  parts.  It  is  in  almost  universal  use 
among  the  practical  chemists,  calico  printers,  dyers,  and 
bleachers,  in  England,  Ireland,  Scotland,  and  America. 
Its  numbers  are  arranged  on  six  glasses,  which  are  called, 
a  whole  set,  (as  the  workmen  term  them.)  No.  1  reach¬ 
es  to  24,  No.  2  to  48,  No.  3  to  74,  No.  4  to  102,  No.  5 
to  138,  No.  6  to  170. 

beaume’s  hydrometer. 

There  are  two  hydrometers  which  have  been  brought 
into  use  by  Beaume,  a  chemical  manufacturer  of  Paris, 
which  are  of  easy  construction,  a  point  to  which  Beaume 
was  particularly  attentive  in  all  his  apparatus.  Beaume’s 
hydrometer  for  salts  is  sometimes  used  amongst  the  calico 
printers,  bleachers,  &c.;  and  I  have  often  wondered  why 
it  was  not  more  generally  adopted,  as  it  answers  every  pur¬ 
pose  of  Twedale’s  six  glasses.  The  only  objection  that 
can  be  made  against  it  is,  that  they  cannot  arrive  at  that 
point  of  accuracy  which  can  be  come  at  on  Twedale’s  ; 
but  even  this  objection  is  groundless,  providing  a  little 
care  is  exercised  in  ascertaining  the  strength  of  liquids. 
The  following  table  will  show  the  correspondence  between 
Beaume,  Twedale,  and  specific  gravity,  which  may  prove 
to  be  of  practical  utility. 


45S 


HYDROMETERS, 


Bepume 

Twedale 

Specific 

Gravity. 

Beaume 

Twedale 

Specific 
’  Gravity. 

0 

0 

1.000 

38 

72 

1.359 

1 

n 

1.007 

39 

74* 

1.372 

2 

2* 

1.014 

40 

77* 

1.3S4 

3 

a* 

1.022 

41 

so* 

1.398 

4 

1.029 

42  ' 

S2* 

1.412 

5 

6* 

1.036 

43 

S5* 

1.426 

\  i  6 

8 

1.044 

44 

88* 

1.440 

7 

9* 

1.052 

45 

91 

1.454 

■  8 

Hi 

1.060 

46 

•94* 

1.470 

9 

12* 

1.067 

47 

97 

1.485 

10 

14* 

1.075 

48 

100 

1.501 

11 

16  4" 

1.083 

49 

103* 

1.526 

12 

18 

1.091 

50 

106* 

1.532 

13 

19* 

1.100 

51 

109* 

1.549 

14 

21* 

1.108 

52 

112* 

1.566 

15 

23 

1.116 

53 

115* 

1.583 

16 

24* 

1.125 

54 

118* 

1.601 

17 

„  26* 

1.134 

55 

123 

1.618 

18 

28 

1.143 

56 

127* 

1.637 

19 

30 

1.152 

57 

131* 

1.656 

20 

32 

1.161 

58 

136* 

1  676 

21 

34 

1.171 

59 

139* 

1.695 

22 

36 

1.180 

60 

142* 

1.714 

23 

38 

1.190 

61 

147* 

1.736 

24 

40 

1.199 

62 

151* 

1.758 

25 

42 

1.210 

63 

155* 

1.779 

26 

44 

1.221 

64 

160* 

1.801 

27 

46 

1.231 

.  65 

165* 

1.S23 

28 

48 

1.242 

66 

170 

1.847 

29 

50 

1.252 

67 

— 

1.872 

30 

52* 

1.261 

68 

_ 

1.897 

31 

54* 

1.275 

69 

_ 

1.921 

32 

56* 

1.2S6 

70 

— — 

1.946 

33 

59 

1.298 

71 

— 

1.974 

34 

61* 

1.309 

72 

_ 

2.002 

35 

64* 

1.321 

73 

2.031 

36 

66* 

1.334 

74 

— 

2.059 

37 

68* 

1.346 

75 

— 

2.087 

APPENDIX. 


469 


APPENDIX. 


Form  of  a  Common  Negotiable  Note. 


$500  00 

Philadelphia,  May  12th ,  1839. 

Sixty  days  after  date,  I  promise  to  pay  to  the  order  ol 
John  Slater,  five  hundred  dollars,  without  defalcation,  for 
value  received.  _  John  O’Neil. 


Note  ivith  Security. 


$250  00 


Philadelphia,  June  — ,  1839 

We,  or  either  of  us,  promise  to  pay  John  Fox,  or  order, 
two  hundred  and  fifty  dollars,  on  the  ninth  day  of  June, 
one  thousand  eight  hundred  and  thirty-nine,  tor  value  re¬ 
ceived,  without  defalcation.  W itness  our  hands  this  —  - 

day  of  March,  one  thousand  eight  hundred  and  thirty-nine. 

J  James  Pilkington 

James  Arkwright. 

Bill  of  Exchange. 


$1000  00 

Philadelphia,  March  27tli,  1839. 

Thirty  days  after  sight,  pay  to  John  Brown,  or  order, 
this  my  first  bill  of  exchange,  for  one  thousand  dollars, 
second  and  third  of  same  tenor  and  date  not  being  paid, 
without  further  advice  from 

Y our  humble  servant, 

John  Grier. 

To  John  Delany ,  Esq.,  New  York . 

40 


470 


APPENDIX. 


Promissory  Note. 

$250  00 


Philadelphia ,  .March  2d,  1839. 

Nine  months  after  date,  I  promise  to  pay  to  Peter  Pratt, 
or  order,  the  sum  ot  two  hundred  and  fifty  dollars,  for 
value  received,  without  defalcation.  Witness  my  hand 
this  second  day  ot  March,  one  thousand  eight  hundred 
and  thirty-nine.  George  Car. 

No  ivitness  required. 

Note  with  Interest 

I  promise  to  pay  John  Selby,  or  order,  the  sum  of  three 
hundred  dollars,  on  demand,  with  interest  till  paid,  for  value 
received,  without  defalcation.  Witness  my  hand,  this  first 
day  ot  May,  one  thousand  eight  hundred  and  thirty-nine. 

Bichard  Baxter. 

Form  oj  an  Inland  Draft  for  .Money,  with  Jlcceptance. 
$750  00 


Philadelphia ,  .May  12 Ih,  1839. 
Six  months  after  date,  pay  to  the  order  of  Henry  Wild, 
seven  hundred  and  fifty  dollars,  for  value  received,  and 
place  the  same  to  my  account.  James  M.  Brown. 
To  Mr.  Elv  Hall,  \ 

JMerchant,  l 

Baltimore.  j  Accepted, 

Abraham  Cook. 

•  - 

Bill  of  Lading. 

Shipped,  in  good  order,  and  well  conditioned,  by  Jabez 
Hill,  on  board  the  called  the  whereof 

is  master,  now  lying  in  the  port  of 
and  bound  for  to  say 

being  marked  and  numbered,  as  in  the  margin,  and  are  to 
bo  delivered  in  the  like  order  and  condition,  at  the  port  of 
the  dangers  of  the  seas  only  excepted,  unto 


APPENDIX. 


471 


or  to  assigns,  paying 

freight  for  the  said  with 

primage  and  average  accustomed. 

In  witness  whereof,  the  master  or  mate  of  the  said  vessel 
hath  affirmed  to  bills  of  lading,  all  of  this  tenor 

and  date,  one  of  which  being  accomplished,  the  others  to 
stand  void,  dated  in  the 

day  of  183 


Bill  of  Parcels. 

Philadelphia,  January  30th,  1839. 
Mr.  John  Hopkins, 

Bought  of  James  Pilkington, 

2  doz.  Domestic  shawls,  a  $2.25  per  doz.  $4.50 


2£  “ 

Silk  handkerchiefs 

9.50 

66 

23.75 

5  “ 

Double  strap  suspenders 

2.25 

66 

11.25 

3  “ 

!  hose, 

4.00 

66 

12.00 

l-i.  u 

1  l  2 

Fine  Penknives, 

3.00 

66 

4.75 

n  “ 

Best  Ptazors, 

8.75 

66 

21.87A 

33  yds. 

Domestic  muslin, 

a  12  per  yd. 

3.96 

25  “ 

Satinet, 

95 

66 

23.75 

5  pieces  Calico,  165!  yds., 

12 

66 

19.86 

$125.69£ 


Receipt — General  form. 

Philadelphia,  April  2d,  1839. 
Received  of  Mr.  Harlan  Page,  two  hundred  and  seventy 
dollars,  in  full,  for  balance  of  account. 

John  Newton. 

$270  00 


Letter  of  Credit. 

Messrs.  Carick  &  Rogers, — Gentlemen , 

Allow  me  to  introduce  to  your  firm  the  bearer,  James 
Pilkington,  a  gentleman  about  commencing  business. 
Should  he  make  a  selection  from  your  stock  to  the  amount 
of  five  hundred  dollars,  I  will  be  answerable  for  that  sun 
in  case  of  his  non-payment.  With  esteem,  yours, 

Simon  Pike. 


472 


APPENDIX. 


FOREIGN  COINS, 


With  their  value  in  Federal  money 


D. 

c. 

in 

A  johannes, 

- 

16 

00 

0 

A  doubloon, 

- 

- 

14 

93 

0 

A  half  johannes, 

- 

8 

00 

0 

A  rnoidore, 

- 

m 

6 

00 

0 

An  old  English  guinea, 

- 

4 

66 

6  * 

A  French  guinea, 

- 

- 

4 

60 

0 

An  English  sovereign, 

• 

4 

44 

4 

Pound  of  Ireland, 

m 

- 

4 

10 

2 

A  Spanish  pistole,  - 

m 

3 

77 

7 

A  French  pistole, 

- 

- 

3 

68 

6 

A  pound  flemish  of  Amsterdam, 

2 

42 

7 

Pagoda  of  India, 

- 

m 

1 

94 

0 

A  sequin  of  Arabia, 

- 

1 

66 

6 

An  oz  of  Persia, 

- 

• 

1 

48 

2 

Tale  of  China, 

- 

1 

48 

0 

Millree  of  Portugal, 

- 

• 

1 

27 

3 

English  or  French  crown, 

- 

1 

10 

0 

Dollar  of  Spain, 

• 

m 

1 

00 

0 

Rix  dollar  of  Sweden, 

m 

1 

02 

5 

Rix  dollar  of  Denmark, 

- 

• 

1 

01 

3 

Scudo  of  Rome, 

m 

96 

0 

A  ducat  of  Naples, 

m 

• 

75 

5 

Ruble  of  Russia, 

m 

71 

3 

Rupee  of  Bengal, 

m 

- 

55 

5 

A  florin  of  Vienna, 

m 

46 

6 

Guilder  of  Holland, 

• 

• 

39 

0 

Marc  banco  of  Hamburg, 

. 

S3 

3 

Piastre  of  Constantinople, 

m 

• 

24 

3 

An  English  shilling, 

22 

2 

A  Pistareen, 

m 

• 

* 

20 

0 

Livre  touruois  of  France, 

m 

m 

17 

6 

A  franc,  - 

• 

* 

17 

9 

A  lira  of  Florence,  • 

• 

m 

m 

15 

0 

Real  of  Spain,  - 

- 

- 

m 

9 

7 

APPENDIX 


478 


STERLING  MONEY, 

With  the  par  value  in  dollars,  cents  and  mills. 


Sterling. ' 

r  United  Slates 

£  s.  d. 

$  cis.  m. 

1 

1  8 

2 

3  7 

rs 

0 

5  5 

'  4 

7  4 

5 

9  2 

6 

11  1 

7 

12  9 

8 

14  8 

9 

16  6 

10 

18  5 

11 

20  3  . 

1  0 

22  2 

1  6 

33  3 

2  0 

O 

44  4 

2  6 

>■  55  5 

3  0 

66  6 

3  6 

77  7 

4  0 

88  8 

4  6 

1  00  0 

5  0 

1  11  1 

5  6 

1  22  2 

6  0 

1  33  3 

6  6 

1  44  4 

7  0 

1  55  5 

7  6 

1  66  6 

8  0 

1  77  7. 

8  6 

1  88  8 

9  0 

2  00  0 

9  6 

2  11  1 

10  0 

2  22  2 

20  Oj 

4  44  4 

474 


appendix 


Sterling. 
£  s.  d. 


10  0  0 
20  0  0 
30  0  0 
40  0  0 
50  0  0 
100  0  0 
500  0  0 
1,-000  0  0 
5,000  0  0 
10,000  0  0, 


United  States. 
Dolls,  cts.  m. 
44  44  4 
88  88  8 
133  33  3 
177  77  7 
222  22  2 
444  44  4 
2,222  22  2 
4,444  44  4 
22,222  22  2 
44,444  44  4 


DOLLARS  AND  CENTS, 


With  their  par  value  in  English  money. 


Dolls. 

cts. 

50 

60 

70 

80 

90 

1 

00 

2 

00 

3 

00 

4 

00 

5 

00 

10 

00 

20 

00 

30 

00 

40 

00 

50 

00 

100 

00 

500 

00 

1,000 

00 

5,000 

00 

10,000 

00 

50,000 

00  J 

£  s.  d. 

2  3 

2  8 

3  1 

3  7 

4  0 

4  6 

9  0 

13  6 
18  0 
1  2  6 
2  5  0 

4  10  0 
6  15  0 
9  0  0 

115  0 
22  10  0 
112  10  0 
225  0  0 

1,125  0  0 

2,250  0  0 
11,250  0  0 


476 


APPENDIX, 


No.  1. 


No.  2. 


No.  3. 


No.  4. 


No.  6. 


APPENDIX, 


477 


No.  7. 


No;  8. 


No.  10. 


No.  11.  No.  12. 


478 


APPENDIX. 


No.  13. 


APPENDIX. 


479 


MECHANICAL  MOVEMENTS. 

No.  1, 

Is  the  ingenious  contrivance  of  the  celebrated  Montgol. 
tier,  generally  called  the  hydraulic  ram.  In  this  apparatus, 
a  current  of  water  must  flow  through  the  tube,  in  the  direc¬ 
tion  of  the  arrow,  and  escape  at  the  lower  valve  which  is 
kept  open  by  a  weight  or  spring,  calculated  according  to 
the  current ;  so  that  when  the  current  arrives  at  its  speed, 
this  valve  is  closed,  and  the  momentum  which  the  water 
has  acquired,  forces  open  the  upper  valve  which  leads  to 
an  air  chamber  above,  where  the  portion  of  the  water  which 
has  passed  the  valve  is  received,  and  thence,  conducted  in 
any  required  direction.  As  soon  as  the  water  which  pass¬ 
es  through  the  upper  valve  has  come  to  a  state  of  equilib¬ 
rium,  the  stream  at  the  arrow  is  necessarily  at  rest,  and  the 
lower  valve  is  again  opened  by  the  spring  or  weight,  at  the 
same  time  that  the  valve  leading  to  the  air  vessel  is  shut ; 
thus  by  the  alternate  action  of  the  two  valves  a  portion  oi 
the  stream  is  raised  at  every  stroke,  and  carried  to  a  reser¬ 
voir  above. 

No.  2, 

Represents  a  section  of  the  oscillating  column  invented 
by  M.  Mannoury  d’  Ectot,  for  the  purpose  of  elevating  a 
portion  of  a  given  fall  of  water,  above  the  level  of  the 
reservoir  or  head  by  means  of  a  machine,  all  the  parts  ot 
which  are  absolutely  fixed.  It  consists  of  an  upper  or 
smaller  tube  which  is  constantly  supplied  with  water,  and 
the  lower  or  larger  tube  constructed  with  a  circular  plate  in 
the  centre  of  the  office,  which  receives  the  stream  from  the 
tube  above.  Upon  allowing  the  water  to  descend  it  forms 
itself  gradually  into  a  cone  on  the  circular  plate,  whicn 
cone  protrudes  into  the  smaller  tube,  so  as  to  stop  the  flow 
of  water  downwards,  and  the  regular  supply  continuing 
from  above,  the  column  in  the  upper  tube  rises  until  the 
cone  on  the  circular  plate  gives  way  ;  this  action  is  re¬ 
newed  periodically,  and  is  regulated  by  the  supply  of  water* 


460 


AITENDIX. 


No.  3  and  4, 

Are  horizontal,  and  overshot  water  wheels. 

No.  5, 

Represents  a  revolving  perpendicular  shaft,  carrying 
two  balls  which  vibrate  on  levers,  supported  on  a  common 
centre  above  ;  these  balls  being  acted  on  by  the  centrifugal 
force,  fly  out  according  to  the  velocity  of  the  shaft.  On 
the  upper  part  of  the  shaft  is  placed  a  loose  collar,  con¬ 
nected  to  the  opposite  ends  of  the  levers  which  carry  the 
two  balls,  which  by  their  position  either  elevate  or  depress 
the  loose  collar,  and  regulate  the  valve  on  the  right,  with 
which  it  is  connected — this  arrangement  is  generally  used 
to  regulate  the  supply  of  steam  to  engines. 

No.  6, 

Is  an  application  of  the  governor  for  regulating  the  sup¬ 
ply  of  water  to  wheels.  The  horizontal  wheel  is  fixed  to 
the  revolving  shaft,  which  receives  motion  from  the  water 
wheel,  the  speed  of  which  is  calculated  to  place  the  balls 
in  the  position  here  represented ;  hut  should  it  increase 
and  thereby  raise  the  sliding  piece,  a  projection  from  the 
left  of  the  shaft  would  strike  against  the  part  immediately 
above,  and  traverse  the  coupling  on  the  horizontal  shaft 
below,  into  gear  with  the  left  haxid  bevil,  which  being  con¬ 
nected  with  the  shaft,  depresses  the  shuttle  of  the°water 
wheel,  and  reduces  the  speed  ;  but  should  the  speed  go 
too  slow,  and  the  balls  collapse,  the  same  projection  would 
strike  against  the  part  immediately  beneath  it,  and  tho 
bevil  on  the  right  would  be  connected  with  the  shaft  and 
turn  it  in  an  opposite  direction,  thereby  raising  the  shuttle 
for  a  greater  supply  of  water. 

No.  7. 

This  is  an  useful  governor  for  pumping  engines,  in  which 
the  work  is  suddenly  varied.  The  solid  piston  here  repre¬ 
sented  does  not  fit  tight  to  the  cylinder,  which  beiug  filled 
with  water  is  compelled  to  escape  through  the  space,  when 


APPENDIX. 


461 


the  passage  on  the  right  hand  is  shut,  and  thus  work  is 
thrown  on  the  engine  ;  but  supposing  the  governor  to  re¬ 
sume  its  proper  position,  the  valve  in  this  side  passage  is 
opened,  and  the  piston  traverses  without  resistance. 

No.  8  and  9. 

Two  arrangements  for  producing  circular  motion,  by 
the  hands  or  feet. 

■  No.  10, 

Is  the  universal  joint  generally  attributed  to  Dr.  Hook, 
by  means  of  which  the  rotary  motion  of  a  shaft  may  be 
conveyed  out  of  the  straight  line,  without  breaking  its 
continuity. 

No.  11 

Is  an  arrangement  of  spur  wheels  running  loose  on  their 
respective  shafts,  with  which  they  can  be  connected  by 
clutch  boxes,  so  that  the  relative  speed  of  the  driver  and 
the  driven  can  be  varied  according  to  the  proportion  of  the 
wheels  which  are  connected  to  the  shafts. 

No.  12, 

#  1 

Is  a  combination  of  wheels  running  loose  on  their  re¬ 
spective  shafts,  which  will  produce  a  variety  of  speeds  in 
a  similar  manner  to  the  one  last  mentioned. 

No.  13. 

Supposing  the  upper  circle  to  represent  a  section  of  two 
drums  close  to  each  other,  and  running  in  opposite  direc¬ 
tions,  the  endless  band  which  passes  over  the  carrier  pulley, 
below,  will  impart  motion  to  the  horizontal  warve  at  the 
lower  end  of  the  perpendicular  screw,  which  is  supported 
by  the  upper  and  lower  arms,  but  carries  the  central  pieces 
as  a  moveable  nut ;  to  this  nut  is  connected  a  fork,  which 
at  each  extreme  of  its  traverse  vibrates  the  weighted  lever, 
and  thereby  passes  the  endless  band  from  one  drum  to  the 
other,  and  reverses  the  revolution  of  the  screw. 

41  2F 


462 


APPENLIX. 


No.  14, 

Is  a  machine  proposed  by  M.  Grandjean  for  cutting 
screws,  in  which  the  piece  to  be  cut  is  traversed,  by  means 
of  the  bent  lever  on  the  left,  which  is  acted  on  by  the  same 
treadle  which  gives  the  rotary  motion. 

No.  15, 

_  Represents  a  machine  for  driving  piles,  in  which  the 
circular  motion  of  the  central  perpendicular  shaft  is  con¬ 
verted  into  alternate  perpendicular  motion,  in  the  weight 
on  the  left.  The  principal  contrivance  by  which  the  weight 
is  relieved  when  at  its  highest  elevation,  is  effected  by  the 
progressive  increase  of  the  coils  of  rope  on  the  central 
shaft,  which  press  on  a  small  lever  seen  to  the  right  hand, 
and  disengages  the  upper  part  of  the  shaft,  and  allows  the 
weight  to  run  down ;  the  upper  part  of  the  shaft  being 
again  re-connected  as  soon  as  the  rope  has  run  off. 

No.  16. 

Suppose  the  upper  part  of  this  figure  to  represent  the 
sails  of  an  horizontal  mill,  or  any  sufficient  moving  power 
to  revolve  the  shaft  which  carries  the  spiral  or  worm  below, 
and  the  shaft  coupled  immediately  below  the  sails  so  as  to 
allow  a  small  vibration,  thereby  allowing  the  spiral  or  worm, 
to  act  on  only  one  wheel  at  a  time.  At  the  back  of  these 
wheels  and  on  the  same  shafts  are  placed  pulleys,  over 
which  a  rope  is  passed,  carrying  a  bucket  at  each  extremi¬ 
ty,  one  ol  which  is  elevated  at  the  same  time  that  the  other 
is  lowered,  by  the  alternative  action  of  the  worm  on  the 
opposite  wheels.  In  the  centre,  and  immediately  below 
the  worm  is  placed  a  vibrating  piece,  against  which  the 
bucket  strikes  in  its  ascent,  and  which,  by  means  of  an 
arm  connected  with  the  step  in  which  the  worm  shaft  is 
supported,  traverses  the  worm  from  one  wheel  to  the  other, 
by  which  means  the  bucket  which  has  delivered  its  water 
is  again  lowered,  at  the  same  time  that  the  opposite  one  is 
elevated. 


INDEX 


A. 

Acetates  . Page 

- of  potass . 

- of  ammonia . 

- of  lead  . 

- - -  of  copper  . 

Acetrometer  . 

Acids . 

Acid,  aceric  . 

- acetic  . 

- amniotic . 

- arsenious . 

- henzoic . 

- butyric  . 

- camphoric . 

- :  carbonic  . 

-  cascic  . 

- chloric  . 

- chloriodic . 

— —  chromic  . 

-  citric  . 

- columbic . 

- delphinic . 

- elogic  . 

- fluoric . 

- gallic . 

- hydriodic  . 

-  iodic  . 

-  laccic  . 

- lactic . 

- lithic  . . . 

- malic . 

- margaritic  . 

- meconic  . 

- melassic  . 

- mellitic . 

- menispermic  . 

- molybdic  . . 

- molybdenous . 

- mucic  . 

- muriatic . 

- nitric  . 

- nitrous  . 

- nitro-muriatic . 

•  —  sulphuric  . 

—  oleic  . . . 

. oxalic  . . . 

32 


Acid,  oxymuriatic  .  185 

-  phosphoric  ...  ......  189 

-  phosphorous  .  188 

- prussic  . 188 

- pyroligneous .  190 

- rosacic  . . . . ,  .  193 

- rucumic  . . . . .  .  193 

- sebacic  .  193 

- selinic .  194 

- sorbic . 194 

- stanic  .  196 

- suberic  .  196 

- succinic .  .  196 

- sulphuric .  197 

- sulphurous  .  198 

- tartaric .  199 

- telluric  . 200 

- tungstic  .  200 

- tungstous  . 201 

- zumic .  .........  201 

-  zonic  ......  . 201 

Adapter .  45 

Aerometer .  45 

Affinity .  18 

Air  . 18.  82 

Alchymy .  18 

Alchemist .  19 

Alembic  .  45 

Aluming,  for  dyeing .  354 

Albumen .  230.  242 

Alcohol .  85 

Alloy .  19 

Alkalies .  19.  201 

Alkalometer .  45 

Almometer .  45 

Amber . 249 

Ammonia  . 206 

Analysis,  chemical .  2C 

Annetto  on  cotton  . 365 

- on  silk . 365 

Antimony .  140 

Animal  substances .  241 

Annealing  of  steel  and  iron  ■  281 

Apparatus .  21 

Arsenic .  137 

Assay  .  21 


Astringent . 

(373) 


219 

219 

219 

220 

220 

45 

156 

157 

157 

159 

159 

158 

160 

161 

161 

1G3 

163 

164 

165 

165 

167 

167 

168 

168 

170 

171 

171 

172 

172 

173 

173 

174 

175 

175 

175 

177 

177 

178 

178 

179 

180 

182 

183 

183 

183 

184 


184 


IN'DKX 


Asphaltnm . 

Astronomy . 

Atoms . 

Attraction .  23 

B. 

Balsams  . 

Barometer . 

Basis . 

Bird-lime  . 

Bismuth  . 

Bitumen  . 

Bituminous  substances  . 

Black  on  silk  . 

- on  cotton . 

- on  thread  . 

— —  on  leather . 

- on  woollen  inclining  to 

nurole . 

inclining  to  brown 


247 

270 

22 

310 


233 

46 

2.7 

232 

)35 

247 

247 

356 

367 

363 

370 

360 


- jet  on  woollen  .... 

- ink  . 

Blacking,  to  make . 

...  328 

Blowpipe . 

Blood* . 

Blue  ink . 

Caloric  . 

Calorimeter . 

Ca  idles,  imitation  of  wax  . . . 
Caoutchouc,  or  India  rubber 
how  dissolved  . . 

- -  its  uses . 

Carburet  .  ... 

Carbon  . 

Carboratcs . 

Carbonates  . 

Carbonate  of  lime  . 

Carbonic  oxide . 

Cartilage . 

Caustic  . 

Cawk . 

Cementation . 

Cement,  block-cutters  . 

- fire  and  waterproof  . 

- —  elastic,  for  belts  . . . 

-  —  for  broken  earthen¬ 
ware  . 

- for  cast-iron  pipes  and 

logs . 333 


■  prussian,  on  woollen. . .  361 

•  on  silk  . 355.  356 

on  leather .  370 

on  straw  .  369 

vat,  on  woollen .  369 

vitriol  . 213 

vat,  for  cotton .  369 


—  a  variety 


Boots  and  shoes,  to  render 


and 


.337.  339 


Bones  . 

- to  whiten  . 

....  350 

- to  dye  and  colour  . 

....  350 

Borates  . 

Bronzing . 

Brown  on  woollen  . 

- red  cast . 

- olive  cast . 

- inclining  to  snuff  . 

. ...  360 

- on  silk . 

3r>" 

■ - on  silk  dress . 

- on  cotton . 

....  366 

Huff  on  cotton  . 

C. 

Calcareous . 

Calcination . . 

Central  forces 

Centre  of  gravity . 

Cerium  . 

Cloth,  to  render  wind 

waterproof . 

Chemical  apparatus . 

- nomenclature . 

- terms  explained  . . . . 

Chlorate  . 

Clock-work . 

j  Chromium  . 

Celicium . 

Clinometer . 

Coagulation  . 

Cobalt  . 

Columbium . 

Colouring  matter . 

Combination . 

Combustion  .  27 

Compound . 

- machines  . 

Common  salt  . 

- -  slide  rule . 

Concentration . 

Concretion  . 

Condensation . 

Copal,  to  dissolve  in  alcohol 
— - in  turpentine 


m 

46 

352 

338 

339 
26 
71 

218 

217 

217 

226 

246 

26 

26 

26 

340 

326 
344 

344 

327 
339 
312 
312 
154 

343 

59 

11 

18 

27 

320 

152 

46 

27 

147 

154 

232 

27 

255 

27 

3U 

215 

298 

27 

27 

27 

329 

329 


INDEX 


485 


Jopal,  to  dissolve  in  fixed  oil  .  331 


Copper . 115.283 

Corks  for  bottles  .  348 

Crimson  on  silk . 358 

Crane  . I .  202 

Crucible  .  46 

Crystallization  . 27.251 

Cupellation .  28 

Cucurbits  .  46 

Cupel . 46 

D. 

Decantation  .  28 

Decoction .  28 

Decomposition .  28 

Decrepitation  .  20 

Deflagration .  29 

Deliquescence  .  29 

Deplegmation .  29 

Dephlogisticated .  29 

Description  of  the  lines  of 

the  slide-rule  .  298 

Desiccation  .  29 

Descensus .  29 

Detonation  .  29 

Digestion  . 29 

Digester  .  47 

Distillation . 29 

Ductility .  29 

Dove  on  silk .  358 

Drab  on  silk . 358 

- on  woollen  .  362 

- on  cotton .  366 

Drunkards,  to  cure  . 351 

Dyeing,  remarks  on .  353 

- material  names  of  . .  368 

E. 

Ebony,  to  imitate .  349 

Ebullition .  30 

Effervescence .  .  30 

Efflorescence .  30 

Elastic . ^  30 

Electricity  . 258 

Eliquation .  30 

Equivalents  . 30 

Essence . 30 

Etherial  .  30 

Ether .  87 

Eudiometer . 47 


Evaporation  . 

Evaporating  vessels  . 

.  47 

Extract . 

.  30 

Extractive  matter  . . 

F. 

Fermentation . 

.  31 

Fibrin . 

. 242 

Filteration  . 

Fire  and  waterproof  cement  326 

Fixed  . 

Fluate . 

.  32 

Filiates . 

. 207 

Flesh  colour  on  silk  . 

.  358 

Fluate  of  lime  . 

.  218 

-  of  silex . 

.  218 

.  32 

.  32 

.  32 

Fly  wheels . 

. 317 

.  317 

Fulmination . 

.  33 

Fusion . 

.  33 

.  47 

G. 

Galvanism . 

One,  . 

. . 33.  84 

Gasometer . 

Gcnometer  . 

.  48 

. 230 

. 340 

- on  calf  and  sheep-skin  348 

Glauber’s  salts ...... 

Gloss,  to  put  on  silk 

. . . .  367.  368 

. . . .  246.  296 

method  of  preparing 
and  using .  341 


...  230 

. 

...  96 

to  dye  on  silver  medals 

and  lamellas  through 

and  through  .... 

. ..  347 

Graver’s  improved  method  of 

tempering . 

-  on  woollen  . 

Green  on  cotton . 

.  364 

Green  sulphate  of  iron  . .  • 

. . .  212 

INDEX 


480 


Gum  Arabic . 234 

- British . 236 

- Copal .  236 

- elastic .  237 

- lac  .  237 

- Senegal  .  235 

- tragacanth  . 235 

- resins . 238 

II. 

Hams,  to  cure .  244 

Honey  . 232 

Hands,  easy  method  of  clean¬ 
ing  .  346 

Horn  . 243 

Horn,  to  soften .  345 

Hydrogen .  67 

Hydrometers .  48 

Hygrometers .  49 

Hypoclepsium  .  49 

Hyper-oxymuriate  of  potass  . .  216 

I. 

Ide .  33 

Inclined  plane .  315 

Incineration  .  33 

Inflammable .  33 

Infusion . 33 

Ink,  black .  325 

- blue .  326 

- red .  326 

- Indian  or  China . 342 

Ink  powder . 347 

Indigo,  sulphate  of .  355 

- vats .  369 

lodate  .  33 

Iodide  .  33 

Iron,  to  prevent  from  rusting  347 

- to  give  a  temper  to  cut 

porphyry .  347 

Iron .  118.273 

Iridium .  455 

Ivory,  to  soften .  349 

■ -  dyeing .  342.  349 

— to  whiten  and  polish  . .  350 

J. 

Japanning . 333 

Japan  grounds .  334 

-  work  polishing .  334 


L. 


Lacquer .  , .  33 

Lactate  .  33 


Leather,  different  shades  of 

dyeing .  37C 

Lcvigation .  34 

Lever .  343 

Light .  58 

Lilac  on  woollen . 362 

Liquors,  scalding  and  prepar¬ 
ing  for  dyers . 

Liquefaction  .  34 

Lixivialion .  34 

M. 

Maceration  .  34 

Madder,  French,  how  marked 

according  to  quality . 369 

Magistcry .  34 

Magnetism . 262 

Manganese .  450 

Matter  . .  399 

Maceration .  355 

Maroon  on  silk . 365 

Martial .  34 

Mechanical  exercises . 273 

Men  and  horses,  considered  as 

first  movers  . .  344 

Mechanics .  399 

Menstruum . 34 

Mercury  .  499 

Metallic  oxides . 227 

Metals . . .  gg 

Mildew,  to  remove  from  linen  344 

Milk .  244 

Mill-work .  343 

Mineralize .  34 

Motion . . 

Mother-water .  34 

Maroon  dyeing  on  silk . 356 

Mortar .  49 

Mucilage . 233 

Muffles .  49 

Muriates . 215 

- of  soda  . 215 

- of  potass . 215 

of  ammonia . . .  216 


INDEX 


487 


N. 

Narcotic  principle . 231 

Neutral .  34 

Neutralization .  34 

ickel .  113 

Nitrates .  213 

- of  potass . 213 

- of  soda . 214 

- of  ammonia .  215 

Nitrogen .  66 

O. 

Of  substances .  57 


Oil,  1  oz.  of  which  will  last  as 
long  as  1  lb.  of  any  other. .  348 
Oil  to  prevent  smoking  in  lamps  342 
Oil  to  prevent  pictures  from 


becoming  black . 348 

Oil.,  to  extract  from  any  flower  352 

—  drying,  to  prepare . 336 

Olive  on  silk .  357 

Optics .  267 

Orange  on  cotton . 356 

- on  woollen . 363 

Organic  substances . 228 

Osmium .  155 

Oxides . . . 35.  223 

Oxidation .  35 

Oxygenation .  35 

Oxyiode .  35 

Oxygen .  63 

Oxides  of  nitrogen .  224 

- of  hydrogen . 226 

- - of  sulphur . 226 

- of  phosphorus . 226 

P. 

Paint,  substitute  for .  337 

Palladium .  104 

Pearl-ash . 208 

Pendulums'. . . . 321 

Petrifaction .  35 

Phlegm .  36 

Phlogiston .  36 

Phosphorus .  76 

Phosphates  . . 36.221 

—  - - of  soda . 221 

- of  soda  and  ammonia  222 

- of  lime . 222 

Pink  on  silk . 355 

Pitch . 239 

Platina .  32 


Pneumatics .  ...  264 

Portable  balls  for  taking  spots 

out  of  clothes .  342 

Potassium .  129 

Potass . 203 

Potash . 208 

Precipitation .  36 

Preparation  of  dye  liquors. . .  354 

Principles .  37 

Prussiate  of  iron . 222 

Prussiate  of  potass  and  iron. .  223 

Pulley . 314 

Purple  on  leather . 371 

-  on  cotton .  366 

Putrefaction .  37 

,Pyrites . 317 

Pyroligneous  tar . 239 

Pyrometer .  49 

R. 

Radical .  37 

Rancidity . 37 

Reagent .  37 

Rectification .  40 

Receiver .  53 

Red  sulphate  of  iron . 212 

Red  ink . 326 

Red  on  cotton  . . . 365 

- on  straw . 369 

- Turkey  on  leather . 370 

- on  woollen . 362 

Reduction .  41 

Remarks  on  chemical  apparatus  56 

Repulsion . 311 

Residuum .  41 

Resins . . 233 

Retorts .  53 

Rhodium .  146 

Roasting .  41 

Rosin,  brown  and  yellow  ....  249 

S. 

Sal .  42 

Salifiable .  42 

Salve,  excellent . 339 

Sal  ammoniac . 216 

Saline .  42 

Saline  products . 202 

Salts . 209 

Salt-petre . 213 

Saturation .  42 

Sediment  . .  42 


488 


INDEX. 


Semi .  42 

Simple .  42 

Silver .  109 

Slate  on  silk .  357 

- on  cotton .  366 

• - on  woollen .  363 

Silver,  to  write  on  .  351 

Slide  rule  . 204 

Scale .  204 

Soda . 204 

Soda  water,  to  make .  344 

Sodium .  132 

Soldering .  293 

- of  ferrules . 293 

Solution .  43 

Space .  310 

Specific  gravity .  43 

Spirit .  43 

Spots,  to  remove  from  silk,  &c.  343 

Stratification .  43 

Starch . 229 

Steel,  blueing  of .  280 

Stone  colour  on  silk .  357 

Sub. .  43 

Sublimation . 44 

Suborate  of  soda . 218 

Sub-carbonate  of  soda . 217 

- - - of  potass . 217 

Sugar  .  229 

-  of  lead . 220 

Sulphur .  70 

Sulphate  of  alumine . 210 

• - -  of  indigo .  355 

- of  alumine  and  potass  211 

- - of  copper . 213 

- of  soda . 211 

Sulphites . 213 

Super .  44 

Super-tartrate  of  potass . 220 


Table  of  saline  products  ....  202 

-  of  divisions  for  the  slide 

rule . 299 

Tantalium .  151 

Tanning .  231 

Tartrates .  220 

- —  of  potass  and  soda. . .  221 

- of  potass  and  antimony  221 

Tar . 238 

Tellurium  .  144 

Thermometer . .  53 

Tin  liquor  on  silk,  &c.. .  .308,  369 


Tin  . .  122.286 

Titanium .  152 

Tortoise-shell,  preparation  for  350 

Trituration.; .  44 

Tungsten .  145 

U. 

Undulations,  to  make  on  wood  349 

Uranium .  14Q 

Ureter .  44 

V. 

Viscidity .  45 

Varnish  from  amber . 332 

-  a  variety .  329 

-  copal .  329 

-  for  copperplate  prints  .  332 

-  to  gild  with  without  gold  332 

-  to  engrave  with  aquafor¬ 
tis  .  332 

-  for  harness .  345 

-  to  fasten  the  leather  on 

top-rollers  in  factories  345 

-  shell-lac .  331 

- -  seed-lac .  331 

Vegetables .  228 

Vinegar,  to  increase  strength  of  351 

- to  make .  351 

- - portable .  352 

Volatilization .  45 

w. 

Water .  73 

Waters,  mineral .  80 

W“x . 231 

- "-dry .  45 

- humid .  45 

Wedge .  315 

Whpel-carriages .  319 

Wheel  and  axle .  314 

White-wash  that  will  notrub  off  345 
Wine,  to  restore  that  is  sour  .  351 

- to  correct  the  b  id  taste  351 

Woody  fibre .  232 

W ood,  to  dye  red .  348 

- to  petrify . 350 

Y. 

Yellow  on  cotton .  364  • 

- on  leather . 370 

■ - on  silk. . .  358 

- - —  on  woollen . 363 


Z. 

Zi»c .  127.  293 


INDEX  TO  SUPPLEMENT 


Pags 

Air  Pump  ......  383 

Application  of  Specific  Gravity  -  -  -  -  421 

Appendix  ......  469 

Beaume’s  Hydrometer  .....  467 

Banks  on  Mills  -  394 

Bodies,  Resistance  of,  when  pressed  longitudinally  -  -  409 

Bricklayers’  Work  .....  432—433 

Building  .......  426 

Circles  and  Diameters 
Cold  Water  Pump 
Communication  of  Power 
Condenser  ... 

Diameters  and  Circumferences 
Engine  Powers,  to  calculate 
Examples  on  the  Strength  of  Materials 
Floors,  Laying,  Jointing,  &c.  - 
Fly  Wheels 

Governor  or  Double  Pendulum 
Hot  water  Pump  -  -  - 

Manager’s  Assistant  in  a  Cotton  Mil 
Materials,  Strength  of  - 

Mill  Work  - 

Overshot  Wheel  ... 

Parallel  Motion 
Power  and  Effect  - 
Power,  Communication  of 
Pumps  -  -  -  - 

Steam  Boilers  - 
Steam  Engine 
“  “  rendered  easy 

“  Force  and  Heat  of  - 

Specific  Gravity  of  Metals,  Stones,  Earths,  Resins,  Liquors, 
and  Woods  - 

M  “  compared  with  Beaume  ant 

Hydrometer  Scale 


434 
383 
308 

383 

435 
381 
410 
42G 

385 
336 

384 
443 
407 
405 
393 

386 
395 
393 
399 
376 
375 

436 
386 


-  418—420 
Twedale’s 

.  46 8 


490 


INDEX  TO  SUPn,  EM  ENT. 


Table  showing  the  square  inch  of  the  Area  of  the  Safety 
Valve;  also,  feet  of  Vertical  Height  of  Feed  Pipe, 
measured  from  the  water  line  in  the  boiler  - 
yCfrCeS  ^ca*>  Libs,  of  Pressure  on  the  Safety 

showing  the  Effective  Pressure  in  each  inch  of  the 


Pag* 


377 

37S 


the  Area  equal  to  what  one  horse  power 


Piston, 
will  be 

Showing  the  Force  and  Heat  of  Steam  .  _ 

Showing  the  Height  of  a  Fall  of  Water  in  feet,  the 
I  ime  of  falling  in  seconds  - 

of  Mill  Work . 

showing  the  Relative  Force  of  Overshot  Wheels, 

Steam  Engines,  Horses,  Men  and  Wind  Mills 
showing  Strength  of  Materials  ... 
showing  the  Relative  Weight  that  may  be  borne  by 
different  materials  -  -  _  .  _ 

of  Sizes  and  Strength  of  Chains  ... 

of  Specific  Gravities  of  different  Bodies  -  415 _ 41S 

of  Weight  of  a  Square  foot  of  Cast  and  Malleable 

Iron,  Copper,  and  Lead  ....  4jg 
of  the  Weight  of  a  Lineal  Foot  of  Malleable  and  Cast 

Iron  Bars  -  •  _  m  b  «*417 

of  the  Properties  of  different  Bodies  .  -  "  422 

of  the  Weight  of  Cast  Iron  Pipes  -  423 

of  Boring  and  Turning  -  425. 

Proportions  of  Timbers  for  small  and  large 
buildings  .....  428-429 


382 

38C 

39b 

405 

406  ' 
414 

408 

414 


“  of  Bricklayers’  Work  - 

for  ascertaining  Circles  and  Diameters 
Ihe  Power  of  Steam  Engines,  and  the  method  of  comput 
mg  it  -  .  _  _  _  r 

Timbers,  Proportions  of,  for  large  and  small  buildings 
1  urmng  and  Boring  -  .  .  = 

T  wed  ale’s  Hydrometer  .  .  . 

Undershot  Wheels  -  .  .  _ 

Velocity  of  Water  Wheel 
Watoi 

WaterWheel  . 

“  Pressure  -  .  . 

w  Wheel,  Height  of 

M  “  Velocity  of 

“  “  Number  of  Buckets 


432 

435 


387 
423 
425 
.  4S7 

•  403 

-  395 
391 

3S9— 393 
389 

-  395 
396 

-  397 


, 


,»rO  V 


C*i  -‘w  Si  i*l  Ul  •• 

•  .  • 


»  '  * 


»,  tbtimn*'}  'la  ♦vWJt  #vo«S>H 


. 

*. 


t‘}> 


«  ; 


> 


v 

\ 

\. 


